From f407285e60b87ae102d6b0d9bfd341e9e6b18351 Mon Sep 17 00:00:00 2001
From: david <njorogedavid13@gmail.com>
Date: Fri, 1 May 2026 18:03:00 +0300
Subject: [PATCH] add soft delete logic

---
 backend/app/config.py                         |   4 +-
 backend/app/decorators/decorators.py          |  16 +-
 backend/app/decorators/owned.py               |   7 +-
 backend/app/models/__init__.py                |   2 +
 backend/app/models/base.py                    | 123 +++++
 backend/app/models/board.py                   |   5 +-
 backend/app/models/card.py                    |   5 +-
 backend/app/models/card_label.py              |   5 +-
 backend/app/models/card_link.py               |   5 +-
 backend/app/models/check_item.py              |   5 +-
 backend/app/models/checklist.py               |   9 +-
 backend/app/models/comment.py                 |   5 +-
 backend/app/models/epic.py                    |   5 +-
 backend/app/models/file_attachment.py         |   5 +-
 backend/app/models/label.py                   |  10 +-
 backend/app/models/list_model.py              |   5 +-
 backend/app/models/wiki.py                    |   5 +-
 backend/app/routes/kanban/boards.py           |  42 +-
 backend/app/routes/kanban/card_links.py       |   7 +-
 backend/app/routes/kanban/cards.py            |   4 +-
 backend/app/routes/kanban/checklists.py       |   4 +-
 backend/app/routes/kanban/comments.py         |   2 +-
 backend/app/routes/kanban/epics.py            |   8 +-
 backend/app/routes/kanban/labels.py           |   2 +-
 backend/app/routes/kanban/lists.py            |   2 +-
 backend/app/routes/kanban/wikis.py            |   4 +-
 backend/app/services/storage/file_service.py  |   3 +-
 .../7a0cfda486e1_add_soft_delete_columns.py   | 146 ++++++
 backend/tests/conftest.py                     |   2 +-
 backend/tests/routes/test_boards.py           | 331 +++++++++++-
 backend/tests/routes/test_cards.py            |  35 +-
 backend/tests/routes/test_checklists.py       |   6 +-
 backend/tests/routes/test_comments.py         |   3 +-
 backend/tests/routes/test_epics.py            |   3 +-
 backend/tests/routes/test_labels.py           |   3 +-
 backend/tests/routes/test_lists.py            |  11 +-
 .../routes/test_soft_delete_integration.py    | 496 ++++++++++++++++++
 backend/tests/routes/test_wikis.py            |  14 +-
 38 files changed, 1273 insertions(+), 76 deletions(-)
 create mode 100644 backend/app/models/base.py
 create mode 100644 backend/migrations/versions/7a0cfda486e1_add_soft_delete_columns.py
 create mode 100644 backend/tests/routes/test_soft_delete_integration.py

diff --git a/backend/app/config.py b/backend/app/config.py
index 67710a6..246ec5d 100644
--- a/backend/app/config.py
+++ b/backend/app/config.py
@@ -88,8 +88,8 @@ class TestingConfig(Config):
 
     # Conservative connection pool settings for testing
     SQLALCHEMY_ENGINE_OPTIONS = {
-        "pool_size": 1,  # Only one connection in the pool
-        "max_overflow": 0,  # No overflow connections allowed
+        "pool_size": 2,  # Only one connection in the pool
+        "max_overflow": 2,  # No overflow connections allowed
         "pool_timeout": 30,
         "pool_recycle": 3600,  # Recycle after 1 hour
         "pool_pre_ping": True,  # Verify connections before using
diff --git a/backend/app/decorators/decorators.py b/backend/app/decorators/decorators.py
index 75a4e6a..8c7eec2 100644
--- a/backend/app/decorators/decorators.py
+++ b/backend/app/decorators/decorators.py
@@ -98,14 +98,16 @@ def load_file_accessible_by_uuid(f):
         user_id = get_current_user_id()
         file_uuid = kwargs.get("file_uuid")
 
-        # Try to find file uploaded by user
-        attachment = FileAttachment.query.filter_by(
-            uuid=file_uuid, uploaded_by=user_id
-        ).first()
+        # Try to find file uploaded by user (only active files)
+        attachment = (
+            FileAttachment.query.filter_by(uuid=file_uuid, uploaded_by=user_id)
+            .filter(FileAttachment.status == "active")
+            .first()
+        )
 
         # If not found, check if attached to a Card that belongs to user's board
         if not attachment:
-            # For Card attachments
+            # For Card attachments (only active files)
             card_attachment = (
                 FileAttachment.query.join(
                     Card,
@@ -116,6 +118,7 @@ def load_file_accessible_by_uuid(f):
                 .filter(
                     FileAttachment.uuid == file_uuid,
                     Board.user_id == user_id,
+                    FileAttachment.status == "active",
                 )
                 .first()
             )
@@ -125,7 +128,7 @@ def load_file_accessible_by_uuid(f):
         # If still not found, check if attached to a
         # Comment that belongs to user's board
         if not attachment:
-            # For Comment attachments
+            # For Comment attachments (only active files)
             comment_attachment = (
                 FileAttachment.query.join(
                     Comment,
@@ -137,6 +140,7 @@ def load_file_accessible_by_uuid(f):
                 .filter(
                     FileAttachment.uuid == file_uuid,
                     Board.user_id == user_id,
+                    FileAttachment.status == "active",
                 )
                 .first()
             )
diff --git a/backend/app/decorators/owned.py b/backend/app/decorators/owned.py
index 90f17d8..d9ca106 100644
--- a/backend/app/decorators/owned.py
+++ b/backend/app/decorators/owned.py
@@ -35,6 +35,7 @@ def load_card_owned(f):
     """
     Loads a Card and ensures its Parent Board belongs to the current user.
     Injects 'card' into the route kwargs.
+    Aborts with 404 if not found, not owned, or soft-deleted.
     """
 
     @wraps(f)
@@ -42,10 +43,12 @@ def load_card_owned(f):
         user_id = get_current_user_id()
         card_id = kwargs.get("card_id")
 
-        # Join Board to check ownership securely in one query
+        # Join Board to check ownership and filter soft-deleted cards
         card = (
             Card.query.join(Board)
-            .filter(Card.id == card_id, Board.user_id == user_id)
+            .filter(
+                Card.id == card_id, Board.user_id == user_id, Card.deleted_at.is_(None)
+            )
             .first()
         )
 
diff --git a/backend/app/models/__init__.py b/backend/app/models/__init__.py
index 5fc864c..43be910 100644
--- a/backend/app/models/__init__.py
+++ b/backend/app/models/__init__.py
@@ -1,4 +1,5 @@
 # fmt: off
+from app.models.base import SoftDeleteMixin
 from app.models.board import Board
 from app.models.card import Card
 from app.models.card_label import CardLabel
@@ -14,6 +15,7 @@ from app.models.user import User
 from app.models.wiki import Wiki, wiki_entity_links
 
 __all__ = [
+    "SoftDeleteMixin",
     "User",
     "Board",
     "List",
diff --git a/backend/app/models/base.py b/backend/app/models/base.py
new file mode 100644
index 0000000..6b03c1b
--- /dev/null
+++ b/backend/app/models/base.py
@@ -0,0 +1,123 @@
+from datetime import UTC, datetime
+
+from app import db
+
+
+class SoftDeleteMixin:
+    """Mixin that provides soft-delete functionality.
+
+    Instead of removing rows from the database, records are marked with
+    status='deleted' and a deleted_at timestamp. This preserves data
+    integrity and supports audit/recovery use-cases.
+
+    Usage:
+        class MyModel(db.Model, SoftDeleteMixin):
+            ...
+
+        # Queries
+        MyModel.active().filter_by(name="foo").all()
+
+        # Soft-delete
+        instance = db.session.get(MyModel, 1)
+        instance.soft_delete()
+        db.session.commit()
+
+        # Restore
+        instance.restore()
+        db.session.commit()
+    """
+
+    STATUS_ACTIVE = "active"
+    STATUS_DELETED = "deleted"
+
+    status = db.Column(
+        db.String(20),
+        default=STATUS_ACTIVE,
+        nullable=False,
+        index=True,
+    )
+    deleted_at = db.Column(db.DateTime, nullable=True)
+
+    @classmethod
+    def active(cls):
+        """Return a query scoped to non-deleted records only.
+
+        Usage:
+            Board.active().filter_by(user_id=1).all()
+            Card.active().order_by(Card.pos).all()
+        """
+        return cls.query.filter(cls.status == cls.STATUS_ACTIVE)
+
+    def soft_delete(self):
+        """Mark this record as deleted and cascade to child relationships.
+
+        Every relationship defined with cascade="all, delete-orphan" or
+        cascade="all" is considered a *soft-deletable child* and will also
+        be soft-deleted recursively.
+        """
+        self._do_soft_delete()
+
+    def _do_soft_delete(self):
+        """Internal recursive soft-delete implementation."""
+        now = datetime.now(UTC)
+
+        # Soft-delete children from configured cascade relationships
+        for prop in self.__mapper__.relationships:
+            cascade = prop.cascade
+            if cascade is None:
+                continue
+
+            # Only cascade to relationships that had delete/delete-orphan
+            if not (cascade.delete or cascade.delete_orphan):
+                continue
+
+            # Get the related objects
+            children = getattr(self, prop.key, None)
+            if children is None:
+                continue
+
+            # Handle dynamic/lazy relationships (query-like)
+            if hasattr(children, "all"):
+                children = children.all()
+
+            # Handle single (many-to-one / scalar) relationships
+            if not isinstance(children, list):
+                children = [children] if children else []
+
+            for child in children:
+                if isinstance(child, SoftDeleteMixin):
+                    child._do_soft_delete()
+
+        self.status = self.STATUS_DELETED
+        self.deleted_at = now
+
+    def restore(self):
+        """Restore a soft-deleted record and cascade to children."""
+        self._do_restore()
+
+    def _do_restore(self):
+        """Internal recursive restore implementation."""
+        for prop in self.__mapper__.relationships:
+            cascade = prop.cascade
+            if cascade is None:
+                continue
+
+            if not (cascade.delete or cascade.delete_orphan):
+                continue
+
+            children = getattr(self, prop.key, None)
+            if children is None:
+                continue
+
+            if hasattr(children, "all"):
+                children = children.all()
+
+            if not isinstance(children, list):
+                children = [children] if children else []
+
+            for child in children:
+                if isinstance(child, SoftDeleteMixin):
+                    child._do_restore()
+
+        self.status = self.STATUS_ACTIVE
+        self.deleted_at = None
diff --git a/backend/app/models/board.py b/backend/app/models/board.py
index a640f2d..d2faa8a 100644
--- a/backend/app/models/board.py
+++ b/backend/app/models/board.py
@@ -3,9 +3,10 @@ from datetime import UTC, datetime
 from sqlalchemy.dialects.postgresql import JSONB
 
 from app import db
+from app.models.base import SoftDeleteMixin
 
 
-class Board(db.Model):
+class Board(db.Model, SoftDeleteMixin):
     """Board model for Kanban boards"""
 
     __tablename__ = "boards"
@@ -74,6 +75,8 @@ class Board(db.Model):
             "prefs": self.prefs,
             "label_names": self.label_names,
             "limits": self.limits,
+            "status": self.status,
+            "deleted_at": self.deleted_at.isoformat() if self.deleted_at else None,
         }
 
     def __repr__(self):
diff --git a/backend/app/models/card.py b/backend/app/models/card.py
index 0949ae1..f7d5477 100644
--- a/backend/app/models/card.py
+++ b/backend/app/models/card.py
@@ -3,9 +3,10 @@ from datetime import UTC, datetime
 from sqlalchemy.dialects.postgresql import JSONB
 
 from app import db
+from app.models.base import SoftDeleteMixin
 
 
-class Card(db.Model):
+class Card(db.Model, SoftDeleteMixin):
     """Card model for Kanban cards"""
 
     __tablename__ = "cards"
@@ -108,6 +109,8 @@ class Card(db.Model):
             "badges": self.badges,
             "cover": self.cover,
             "desc_data": self.desc_data,
+            "status": self.status,
+            "deleted_at": self.deleted_at.isoformat() if self.deleted_at else None,
             "parent_card_name": (
                 pl.parent_card.name
                 if (pl := self.parent_links.first()) and pl.parent_card
diff --git a/backend/app/models/card_label.py b/backend/app/models/card_label.py
index 17acde3..2eac06e 100644
--- a/backend/app/models/card_label.py
+++ b/backend/app/models/card_label.py
@@ -1,9 +1,10 @@
 from datetime import UTC, datetime
 
 from app import db
+from app.models.base import SoftDeleteMixin
 
 
-class CardLabel(db.Model):
+class CardLabel(db.Model, SoftDeleteMixin):
     """Many-to-many relationship between cards and labels"""
 
     __tablename__ = "card_labels"
@@ -37,6 +38,8 @@ class CardLabel(db.Model):
             "card_id": self.card_id,
             "label_id": self.label_id,
             "created_at": self.created_at.isoformat() if self.created_at else None,
+            "status": self.status,
+            "deleted_at": self.deleted_at.isoformat() if self.deleted_at else None,
         }
 
     def __repr__(self):
diff --git a/backend/app/models/card_link.py b/backend/app/models/card_link.py
index 49850cc..63de5b9 100644
--- a/backend/app/models/card_link.py
+++ b/backend/app/models/card_link.py
@@ -1,9 +1,10 @@
 from datetime import UTC, datetime
 
 from app import db
+from app.models.base import SoftDeleteMixin
 
 
-class CardLink(db.Model):
+class CardLink(db.Model, SoftDeleteMixin):
     """CardLink model for bidirectional card-to-card relationships"""
 
     __tablename__ = "card_links"
@@ -48,6 +49,8 @@ class CardLink(db.Model):
             "child_card_id": self.child_card_id,
             "created_by": self.created_by,
             "created_at": self.created_at.isoformat() if self.created_at else None,
+            "status": self.status,
+            "deleted_at": self.deleted_at.isoformat() if self.deleted_at else None,
         }
         if include_cards:
             result["parent_card"] = (
diff --git a/backend/app/models/check_item.py b/backend/app/models/check_item.py
index bc8c35d..1682072 100644
--- a/backend/app/models/check_item.py
+++ b/backend/app/models/check_item.py
@@ -1,9 +1,10 @@
 from datetime import UTC, datetime
 
 from app import db
+from app.models.base import SoftDeleteMixin
 
 
-class CheckItem(db.Model):
+class CheckItem(db.Model, SoftDeleteMixin):
     """CheckItem model for checklist items"""
 
     __tablename__ = "check_items"
@@ -45,6 +46,8 @@ class CheckItem(db.Model):
             "user_id": self.user_id,
             "created_at": self.created_at.isoformat() if self.created_at else None,
             "updated_at": self.updated_at.isoformat() if self.updated_at else None,
+            "status": self.status,
+            "deleted_at": self.deleted_at.isoformat() if self.deleted_at else None,
         }
 
     def __repr__(self):
diff --git a/backend/app/models/checklist.py b/backend/app/models/checklist.py
index 90808cf..e61c03d 100644
--- a/backend/app/models/checklist.py
+++ b/backend/app/models/checklist.py
@@ -1,10 +1,11 @@
 from datetime import UTC, datetime
 
 from app import db
+from app.models.base import SoftDeleteMixin
 
 
-class Checklist(db.Model):
-    """Checklist model for Kanban checklists"""
+class Checklist(db.Model, SoftDeleteMixin):
+    """Checklist model for card checklists"""
 
     __tablename__ = "checklists"
 
@@ -45,10 +46,12 @@ class Checklist(db.Model):
             "id": self.id,
             "name": self.name,
             "pos": self.pos,
-            "board_id": self.board_id,
             "card_id": self.card_id,
+            "board_id": self.card.board_id if self.card else None,
             "created_at": self.created_at.isoformat() if self.created_at else None,
             "updated_at": self.updated_at.isoformat() if self.updated_at else None,
+            "status": self.status,
+            "deleted_at": self.deleted_at.isoformat() if self.deleted_at else None,
         }
 
     def __repr__(self):
diff --git a/backend/app/models/comment.py b/backend/app/models/comment.py
index 26894f1..b76ccec 100644
--- a/backend/app/models/comment.py
+++ b/backend/app/models/comment.py
@@ -1,9 +1,10 @@
 from datetime import UTC, datetime
 
 from app import db
+from app.models.base import SoftDeleteMixin
 
 
-class Comment(db.Model):
+class Comment(db.Model, SoftDeleteMixin):
     """Comment model for card comments"""
 
     __tablename__ = "comments"
@@ -50,6 +51,8 @@ class Comment(db.Model):
             "user_id": self.user_id,
             "created_at": self.created_at.isoformat() if self.created_at else None,
             "updated_at": self.updated_at.isoformat() if self.updated_at else None,
+            "status": self.status,
+            "deleted_at": self.deleted_at.isoformat() if self.deleted_at else None,
         }
 
     def __repr__(self):
diff --git a/backend/app/models/epic.py b/backend/app/models/epic.py
index 5e4c137..e3d55d7 100644
--- a/backend/app/models/epic.py
+++ b/backend/app/models/epic.py
@@ -3,9 +3,10 @@ from datetime import UTC, datetime
 from sqlalchemy.dialects.postgresql import JSONB
 
 from app import db
+from app.models.base import SoftDeleteMixin
 
 
-class Epic(db.Model):
+class Epic(db.Model, SoftDeleteMixin):
     """Epic model for tracking large features across multiple cards"""
 
     __tablename__ = "epics"
@@ -81,6 +82,8 @@ class Epic(db.Model):
             "created_at": self.created_at.isoformat() if self.created_at else None,
             "updated_at": self.updated_at.isoformat() if self.updated_at else None,
             "metrics": self.metrics or {"card_count": 0, "completed_cards_count": 0},
+            "status": self.status,
+            "deleted_at": self.deleted_at.isoformat() if self.deleted_at else None,
         }
 
     def __repr__(self):
diff --git a/backend/app/models/file_attachment.py b/backend/app/models/file_attachment.py
index 232a705..1d3d6a5 100644
--- a/backend/app/models/file_attachment.py
+++ b/backend/app/models/file_attachment.py
@@ -4,9 +4,10 @@ from datetime import UTC, datetime
 from sqlalchemy import Index
 
 from app import db
+from app.models.base import SoftDeleteMixin
 
 
-class FileAttachment(db.Model):
+class FileAttachment(db.Model, SoftDeleteMixin):
     """Polymorphic file attachment model for Cards, Comments, and other entities"""
 
     __tablename__ = "file_attachments"
@@ -69,6 +70,8 @@ class FileAttachment(db.Model):
             "attachable_id": self.attachable_id,
             "uploaded_by": self.uploaded_by,
             "created_at": self.created_at.isoformat() if self.created_at else None,
+            "status": self.status,
+            "deleted_at": self.deleted_at.isoformat() if self.deleted_at else None,
         }
 
     def __repr__(self):
diff --git a/backend/app/models/label.py b/backend/app/models/label.py
index b8482ef..27554fe 100644
--- a/backend/app/models/label.py
+++ b/backend/app/models/label.py
@@ -1,10 +1,11 @@
 from datetime import UTC, datetime
 
 from app import db
+from app.models.base import SoftDeleteMixin
 
 
-class Label(db.Model):
-    """Label model for Kanban labels"""
+class Label(db.Model, SoftDeleteMixin):
+    """Label model for card labels"""
 
     __tablename__ = "labels"
 
@@ -40,11 +41,12 @@ class Label(db.Model):
             "id": self.id,
             "name": self.name,
             "color": self.color,
-            "uses": self.uses,
             "board_id": self.board_id,
             "created_at": self.created_at.isoformat() if self.created_at else None,
             "updated_at": self.updated_at.isoformat() if self.updated_at else None,
+            "status": self.status,
+            "deleted_at": self.deleted_at.isoformat() if self.deleted_at else None,
         }
 
     def __repr__(self):
-        return f"<Label {self.name} ({self.color})>"
+        return f"<Label {self.name}>"
diff --git a/backend/app/models/list_model.py b/backend/app/models/list_model.py
index 7708829..68e2571 100644
--- a/backend/app/models/list_model.py
+++ b/backend/app/models/list_model.py
@@ -1,9 +1,10 @@
 from datetime import UTC, datetime
 
 from app import db
+from app.models.base import SoftDeleteMixin
 
 
-class List(db.Model):
+class List(db.Model, SoftDeleteMixin):
     """List model for Kanban lists (columns)"""
 
     __tablename__ = "lists"
@@ -44,6 +45,8 @@ class List(db.Model):
             "board_id": self.board_id,
             "created_at": self.created_at.isoformat() if self.created_at else None,
             "updated_at": self.updated_at.isoformat() if self.updated_at else None,
+            "status": self.status,
+            "deleted_at": self.deleted_at.isoformat() if self.deleted_at else None,
         }
 
     def __repr__(self):
diff --git a/backend/app/models/wiki.py b/backend/app/models/wiki.py
index 8af6c7d..5af30fd 100644
--- a/backend/app/models/wiki.py
+++ b/backend/app/models/wiki.py
@@ -4,6 +4,7 @@ from sqlalchemy import and_
 from sqlalchemy.dialects.postgresql import JSONB
 
 from app import db
+from app.models.base import SoftDeleteMixin
 from app.models.card import Card
 from app.models.epic import Epic
 
@@ -22,7 +23,7 @@ wiki_entity_links = db.Table(
 )
 
 
-class Wiki(db.Model):
+class Wiki(db.Model, SoftDeleteMixin):
     """Wiki model for reusable rich text content within a board"""
 
     __tablename__ = "wikis"
@@ -105,6 +106,8 @@ class Wiki(db.Model):
             "updated_by": self.updated_by,
             "created_at": self.created_at.isoformat() if self.created_at else None,
             "updated_at": self.updated_at.isoformat() if self.updated_at else None,
+            "status": self.status,
+            "deleted_at": self.deleted_at.isoformat() if self.deleted_at else None,
         }
 
     def __repr__(self):
diff --git a/backend/app/routes/kanban/boards.py b/backend/app/routes/kanban/boards.py
index de9e5fb..e1395d9 100644
--- a/backend/app/routes/kanban/boards.py
+++ b/backend/app/routes/kanban/boards.py
@@ -7,7 +7,8 @@ from flask_pydantic import validate
 from app import db
 from app.decorators import load_board_owned
 from app.decorators.decorators import get_current_user_id
-from app.models import Board, Card, CardLabel, Label, List
+from app.models import (Board, Card, CardLabel, CheckItem, Checklist, Comment,
+                        Label, List)
 from app.schemas import (BoardCreateRequest, BoardResponse,
                          BoardWithDetailsResponse)
 
@@ -19,7 +20,7 @@ from . import kanban_bp
 def get_boards():
     """Get all boards for current user"""
     user_id = get_current_user_id()
-    boards = Board.query.filter_by(user_id=user_id).all()
+    boards = Board.active().filter_by(user_id=user_id).all()
     return [BoardResponse.model_validate(board).model_dump() for board in boards], 200
 
 
@@ -30,39 +31,54 @@ def get_board(board_id, board):
     """Get a single board with all its details"""
     from app.models import User
 
-    # Get all lists for this board
+    # Get all lists for this board (filter out soft-deleted lists)
     lists_data = []
-    for lst in board.lists.filter_by(closed=False).order_by(List.pos).all():
+    for lst in (
+        board.lists.filter_by(closed=False, deleted_at=None).order_by(List.pos).all()
+    ):
         cards_data = []
-        for card in lst.cards.filter_by(closed=False).order_by(Card.pos).all():
+        # Filter out soft-deleted cards
+        for card in (
+            lst.cards.filter_by(closed=False, deleted_at=None).order_by(Card.pos).all()
+        ):
             card_dict = card.to_dict()
 
-            # Add labels for this card
+            # Add labels for this card (filter out soft-deleted card-label associations)
             card_dict["labels"] = [
                 label.to_dict()
                 for label in (
                     db.session.query(Label)
                     .join(CardLabel)
-                    .filter(CardLabel.card_id == card.id)
+                    .filter(
+                        CardLabel.card_id == card.id, CardLabel.deleted_at.is_(None)
+                    )
                     .all()
                 )
             ]
 
-            # Add comments for this card
+            # Add comments for this card (filter out soft-deleted comments)
             card_dict["comments"] = []
-            for comment in card.comments.all():
+            for comment in card.comments.filter(Comment.deleted_at.is_(None)).all():
                 comment_dict = comment.to_dict()
                 user = db.session.get(User, comment.user_id)
                 comment_dict["user"] = user.to_dict() if user else None
                 card_dict["comments"].append(comment_dict)
 
-            # Add checklists with items for this card
+            # Add checklists with items for this
+            # card (filter out soft-deleted checklists and items)
             card_dict["checklists"] = [
                 {
                     **checklist.to_dict(),
-                    "items": [item.to_dict() for item in checklist.check_items.all()],
+                    "items": [
+                        item.to_dict()
+                        for item in checklist.check_items.filter(
+                            CheckItem.deleted_at.is_(None)
+                        ).all()
+                    ],
                 }
-                for checklist in card.checklists.all()
+                for checklist in card.checklists.filter(
+                    Checklist.deleted_at.is_(None)
+                ).all()
             ]
 
             # Add epic for this card
@@ -142,7 +158,7 @@ def update_board(board_id, board, body: BoardCreateRequest):
 @load_board_owned
 def delete_board(board_id, board):
     """Delete a board"""
-    db.session.delete(board)
+    board.soft_delete()
     db.session.commit()
 
     return {"message": "Board deleted"}, 200
diff --git a/backend/app/routes/kanban/card_links.py b/backend/app/routes/kanban/card_links.py
index fe13395..9616d0e 100644
--- a/backend/app/routes/kanban/card_links.py
+++ b/backend/app/routes/kanban/card_links.py
@@ -123,7 +123,7 @@ def unlink_card(card_id, link_id):
     if link.parent_card_id != card.id and link.child_card_id != card.id:
         return jsonify({"error": "Link does not belong to this card"}), 403
 
-    db.session.delete(link)
+    link.soft_delete()
     db.session.commit()
 
     return jsonify({"message": "Cards unlinked successfully"}), 200
@@ -204,7 +204,7 @@ def delete_card_link(link_id):
     if not link:
         return jsonify({"error": "Link not found"}), 404
 
-    db.session.delete(link)
+    link.soft_delete()
     db.session.commit()
 
     return jsonify({"message": "Cards unlinked successfully"}), 200
@@ -264,8 +264,7 @@ def convert_check_item_to_card(card_id, check_item_id):
     db.session.add(link)
 
     # Remove the checklist item
-    db.session.delete(check_item)
-
+    check_item.soft_delete()
     db.session.commit()
 
     return (
diff --git a/backend/app/routes/kanban/cards.py b/backend/app/routes/kanban/cards.py
index 66301f9..26119eb 100644
--- a/backend/app/routes/kanban/cards.py
+++ b/backend/app/routes/kanban/cards.py
@@ -146,9 +146,9 @@ def update_card(card_id, card, body: CardCreateRequest):
 @kanban_bp.route("/cards/<int:card_id>", methods=["DELETE"])
 @jwt_required()
 @load_card_owned
-def delete_card(card_id, card):
+def delete_card(card_id, card: Card):
     """Delete a card"""
-    db.session.delete(card)
+    card.soft_delete()
     db.session.commit()
 
     return {"message": "Card deleted"}, 200
diff --git a/backend/app/routes/kanban/checklists.py b/backend/app/routes/kanban/checklists.py
index a7689af..41e3252 100644
--- a/backend/app/routes/kanban/checklists.py
+++ b/backend/app/routes/kanban/checklists.py
@@ -70,7 +70,7 @@ def update_check_item(item_id, check_item, body: CheckItemCreateRequest):
 @load_checklist_owned
 def delete_checklist(checklist_id, checklist):
     """Delete a checklist"""
-    db.session.delete(checklist)
+    checklist.soft_delete()
     db.session.commit()
 
     return {"message": "Checklist deleted"}, 200
@@ -81,7 +81,7 @@ def delete_checklist(checklist_id, checklist):
 @load_check_item_owned
 def delete_check_item(item_id, check_item):
     """Delete a check item"""
-    db.session.delete(check_item)
+    check_item.soft_delete()
     db.session.commit()
 
     return {"message": "Check item deleted"}, 200
diff --git a/backend/app/routes/kanban/comments.py b/backend/app/routes/kanban/comments.py
index e758baf..bbd92e1 100644
--- a/backend/app/routes/kanban/comments.py
+++ b/backend/app/routes/kanban/comments.py
@@ -66,7 +66,7 @@ def update_comment(comment_id, comment, body: CommentCreateRequest):
 @load_comment_owned
 def delete_comment(comment_id, comment):
     """Delete a comment"""
-    db.session.delete(comment)
+    comment.soft_delete()
     db.session.commit()
 
     return {"message": "Comment deleted"}, 200
diff --git a/backend/app/routes/kanban/epics.py b/backend/app/routes/kanban/epics.py
index d328c52..d3b8c39 100644
--- a/backend/app/routes/kanban/epics.py
+++ b/backend/app/routes/kanban/epics.py
@@ -22,7 +22,7 @@ def get_board_epics(board_id):
     if not board:
         return {"error": "Board not found"}, 404
 
-    epics = Epic.query.filter_by(board_id=board_id).all()
+    epics = Epic.active().filter_by(board_id=board_id).all()
     return epics, 200
 
 
@@ -65,7 +65,7 @@ def get_epic(epic_id):
         return {"error": "Epic not found"}, 404
 
     # Get cards for this epic
-    cards = Card.query.filter_by(epic_id=epic_id).all()
+    cards = Card.active().filter_by(epic_id=epic_id).all()
     epic_dict = EpicResponse.model_validate(epic).model_dump()
     epic_dict["cards"] = [card.to_dict() for card in cards]
 
@@ -119,10 +119,10 @@ def delete_epic(epic_id):
         return {"error": "Epic not found"}, 404
 
     # Unlink all cards from this epic
-    Card.query.filter_by(epic_id=epic_id).update({"epic_id": None})
+    Card.active().filter_by(epic_id=epic_id).update({"epic_id": None})
 
     # Delete epic
-    db.session.delete(epic)
+    epic.soft_delete()
     db.session.commit()
 
     return {"message": "Epic deleted successfully"}, 200
diff --git a/backend/app/routes/kanban/labels.py b/backend/app/routes/kanban/labels.py
index 636bed9..a9f98fc 100644
--- a/backend/app/routes/kanban/labels.py
+++ b/backend/app/routes/kanban/labels.py
@@ -73,7 +73,7 @@ def remove_label_from_card(card_id, card, label_id):
     if not card_label:
         return {"error": "Label not found on card"}, 404
 
-    db.session.delete(card_label)
+    card_label.soft_delete()
     db.session.commit()
 
     return {"message": "Label removed from card"}, 200
diff --git a/backend/app/routes/kanban/lists.py b/backend/app/routes/kanban/lists.py
index ff1d5a2..4a33ee9 100644
--- a/backend/app/routes/kanban/lists.py
+++ b/backend/app/routes/kanban/lists.py
@@ -64,7 +64,7 @@ def update_list(list_id, lst, body: ListCreateRequest):
 @load_list_owned
 def delete_list(list_id, lst):
     """Delete a list"""
-    db.session.delete(lst)
+    lst.soft_delete()
     db.session.commit()
 
     return {"message": "List deleted"}, 200
diff --git a/backend/app/routes/kanban/wikis.py b/backend/app/routes/kanban/wikis.py
index 78373d9..37dd259 100644
--- a/backend/app/routes/kanban/wikis.py
+++ b/backend/app/routes/kanban/wikis.py
@@ -37,7 +37,7 @@ def get_board_wikis(board_id):
     if not board:
         return {"error": "Board not found"}, 404
 
-    wikis = Wiki.query.filter_by(board_id=board_id).all()
+    wikis = Wiki.active().filter_by(board_id=board_id).all()
     return wikis, 200
 
 
@@ -147,7 +147,7 @@ def delete_wiki(wiki_id):
         return {"error": "Wiki not found"}, 404
 
     # Delete wiki (cascades to wiki_entity_links)
-    db.session.delete(wiki)
+    wiki.soft_delete()
     db.session.commit()
 
     return {"message": "Wiki deleted successfully"}, 200
diff --git a/backend/app/services/storage/file_service.py b/backend/app/services/storage/file_service.py
index 6bd0995..56bec1a 100644
--- a/backend/app/services/storage/file_service.py
+++ b/backend/app/services/storage/file_service.py
@@ -171,8 +171,7 @@ class FileService:
             current_app.logger.error(f"Error deleting file from MinIO: {e}")
 
         # Delete from database
-        db.session.delete(attachment)
-        db.session.commit()
+        attachment.soft_delete()
 
         current_app.logger.info(f"File deleted: {attachment.original_name}")
         return True
diff --git a/backend/migrations/versions/7a0cfda486e1_add_soft_delete_columns.py b/backend/migrations/versions/7a0cfda486e1_add_soft_delete_columns.py
new file mode 100644
index 0000000..8852b83
--- /dev/null
+++ b/backend/migrations/versions/7a0cfda486e1_add_soft_delete_columns.py
@@ -0,0 +1,146 @@
+"""add soft delete columns
+
+Revision ID: 7a0cfda486e1
+Revises: bf430156bcf2
+Create Date: 2026-05-01 13:40:24.316892
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '7a0cfda486e1'
+down_revision = 'bf430156bcf2'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table('boards', schema=None) as batch_op:
+        batch_op.add_column(sa.Column('status', sa.String(length=20), nullable=False, server_default='active'))
+        batch_op.add_column(sa.Column('deleted_at', sa.DateTime(), nullable=True))
+        batch_op.create_index(batch_op.f('ix_boards_status'), ['status'], unique=False)
+
+    with op.batch_alter_table('card_labels', schema=None) as batch_op:
+        batch_op.add_column(sa.Column('status', sa.String(length=20), nullable=False, server_default='active'))
+        batch_op.add_column(sa.Column('deleted_at', sa.DateTime(), nullable=True))
+        batch_op.create_index(batch_op.f('ix_card_labels_status'), ['status'], unique=False)
+
+    with op.batch_alter_table('card_links', schema=None) as batch_op:
+        batch_op.add_column(sa.Column('status', sa.String(length=20), nullable=False, server_default='active'))
+        batch_op.add_column(sa.Column('deleted_at', sa.DateTime(), nullable=True))
+        batch_op.create_index(batch_op.f('ix_card_links_status'), ['status'], unique=False)
+
+    with op.batch_alter_table('cards', schema=None) as batch_op:
+        batch_op.add_column(sa.Column('status', sa.String(length=20), nullable=False, server_default='active'))
+        batch_op.add_column(sa.Column('deleted_at', sa.DateTime(), nullable=True))
+        batch_op.create_index(batch_op.f('ix_cards_status'), ['status'], unique=False)
+
+    with op.batch_alter_table('check_items', schema=None) as batch_op:
+        batch_op.add_column(sa.Column('status', sa.String(length=20), nullable=False, server_default='active'))
+        batch_op.add_column(sa.Column('deleted_at', sa.DateTime(), nullable=True))
+        batch_op.create_index(batch_op.f('ix_check_items_status'), ['status'], unique=False)
+
+    with op.batch_alter_table('checklists', schema=None) as batch_op:
+        batch_op.add_column(sa.Column('status', sa.String(length=20), nullable=False, server_default='active'))
+        batch_op.add_column(sa.Column('deleted_at', sa.DateTime(), nullable=True))
+        batch_op.create_index(batch_op.f('ix_checklists_status'), ['status'], unique=False)
+
+    with op.batch_alter_table('comments', schema=None) as batch_op:
+        batch_op.add_column(sa.Column('status', sa.String(length=20), nullable=False, server_default='active'))
+        batch_op.add_column(sa.Column('deleted_at', sa.DateTime(), nullable=True))
+        batch_op.create_index(batch_op.f('ix_comments_status'), ['status'], unique=False)
+
+    with op.batch_alter_table('epics', schema=None) as batch_op:
+        batch_op.add_column(sa.Column('status', sa.String(length=20), nullable=False, server_default='active'))
+        batch_op.add_column(sa.Column('deleted_at', sa.DateTime(), nullable=True))
+        batch_op.create_index(batch_op.f('ix_epics_status'), ['status'], unique=False)
+
+    with op.batch_alter_table('file_attachments', schema=None) as batch_op:
+        batch_op.add_column(sa.Column('status', sa.String(length=20), nullable=False, server_default='active'))
+        batch_op.add_column(sa.Column('deleted_at', sa.DateTime(), nullable=True))
+        batch_op.create_index(batch_op.f('ix_file_attachments_status'), ['status'], unique=False)
+
+    with op.batch_alter_table('labels', schema=None) as batch_op:
+        batch_op.add_column(sa.Column('status', sa.String(length=20), nullable=False, server_default='active'))
+        batch_op.add_column(sa.Column('deleted_at', sa.DateTime(), nullable=True))
+        batch_op.create_index(batch_op.f('ix_labels_status'), ['status'], unique=False)
+
+    with op.batch_alter_table('lists', schema=None) as batch_op:
+        batch_op.add_column(sa.Column('status', sa.String(length=20), nullable=False, server_default='active'))
+        batch_op.add_column(sa.Column('deleted_at', sa.DateTime(), nullable=True))
+        batch_op.create_index(batch_op.f('ix_lists_status'), ['status'], unique=False)
+
+    with op.batch_alter_table('wikis', schema=None) as batch_op:
+        batch_op.add_column(sa.Column('status', sa.String(length=20), nullable=False, server_default='active'))
+        batch_op.add_column(sa.Column('deleted_at', sa.DateTime(), nullable=True))
+        batch_op.create_index(batch_op.f('ix_wikis_status'), ['status'], unique=False)
+
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table('wikis', schema=None) as batch_op:
+        batch_op.drop_index(batch_op.f('ix_wikis_status'))
+        batch_op.drop_column('deleted_at')
+        batch_op.drop_column('status')
+
+    with op.batch_alter_table('lists', schema=None) as batch_op:
+        batch_op.drop_index(batch_op.f('ix_lists_status'))
+        batch_op.drop_column('deleted_at')
+        batch_op.drop_column('status')
+
+    with op.batch_alter_table('labels', schema=None) as batch_op:
+        batch_op.drop_index(batch_op.f('ix_labels_status'))
+        batch_op.drop_column('deleted_at')
+        batch_op.drop_column('status')
+
+    with op.batch_alter_table('file_attachments', schema=None) as batch_op:
+        batch_op.drop_index(batch_op.f('ix_file_attachments_status'))
+        batch_op.drop_column('deleted_at')
+        batch_op.drop_column('status')
+
+    with op.batch_alter_table('epics', schema=None) as batch_op:
+        batch_op.drop_index(batch_op.f('ix_epics_status'))
+        batch_op.drop_column('deleted_at')
+        batch_op.drop_column('status')
+
+    with op.batch_alter_table('comments', schema=None) as batch_op:
+        batch_op.drop_index(batch_op.f('ix_comments_status'))
+        batch_op.drop_column('deleted_at')
+        batch_op.drop_column('status')
+
+    with op.batch_alter_table('checklists', schema=None) as batch_op:
+        batch_op.drop_index(batch_op.f('ix_checklists_status'))
+        batch_op.drop_column('deleted_at')
+        batch_op.drop_column('status')
+
+    with op.batch_alter_table('check_items', schema=None) as batch_op:
+        batch_op.drop_index(batch_op.f('ix_check_items_status'))
+        batch_op.drop_column('deleted_at')
+        batch_op.drop_column('status')
+
+    with op.batch_alter_table('cards', schema=None) as batch_op:
+        batch_op.drop_index(batch_op.f('ix_cards_status'))
+        batch_op.drop_column('deleted_at')
+        batch_op.drop_column('status')
+
+    with op.batch_alter_table('card_links', schema=None) as batch_op:
+        batch_op.drop_index(batch_op.f('ix_card_links_status'))
+        batch_op.drop_column('deleted_at')
+        batch_op.drop_column('status')
+
+    with op.batch_alter_table('card_labels', schema=None) as batch_op:
+        batch_op.drop_index(batch_op.f('ix_card_labels_status'))
+        batch_op.drop_column('deleted_at')
+        batch_op.drop_column('status')
+
+    with op.batch_alter_table('boards', schema=None) as batch_op:
+        batch_op.drop_index(batch_op.f('ix_boards_status'))
+        batch_op.drop_column('deleted_at')
+        batch_op.drop_column('status')
+
+    # ### end Alembic commands ###
diff --git a/backend/tests/conftest.py b/backend/tests/conftest.py
index d2e0b7d..3fbaf3d 100644
--- a/backend/tests/conftest.py
+++ b/backend/tests/conftest.py
@@ -14,7 +14,7 @@ log = logging.getLogger(__name__)
 fake = Faker()
 
 
-@pytest.fixture(scope="function")
+@pytest.fixture(scope="session")
 def app():
     """Create application for testing with PostgreSQL database (session scope)"""
     app = create_app(config_name="test")
diff --git a/backend/tests/routes/test_boards.py b/backend/tests/routes/test_boards.py
index 99b4f4f..209a1d1 100644
--- a/backend/tests/routes/test_boards.py
+++ b/backend/tests/routes/test_boards.py
@@ -1,7 +1,8 @@
 import pytest
 
 from app import db
-from app.models import Board, Card, List
+from app.models import (Board, Card, CardLabel, CheckItem, Checklist, Comment,
+                        Label, List)
 
 
 @pytest.mark.integration
@@ -147,7 +148,8 @@ class TestBoardRoutes:
 
         # Verify board is deleted
         deleted_board = db.session.get(Board, board.id)
-        assert deleted_board is None
+        assert deleted_board is not None
+        assert deleted_board.status == "deleted"
 
     def test_delete_board_not_found(self, client, db_session, auth_headers):
         """Test deleting a non-existent board"""
@@ -164,3 +166,328 @@ class TestBoardRoutes:
         response = client.delete(f"/api/boards/{board.id}")
 
         assert response.status_code == 401
+
+    def test_get_board_filters_deleted_cards(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test that soft-deleted cards are filtered out from board response"""
+        # Create board with list and 2 cards
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.flush()
+
+        lst = List(name="To Do", board_id=board.id, pos=0)
+        db_session.add(lst)
+        db_session.flush()
+
+        card1 = Card(name="Active Card", board_id=board.id, list_id=lst.id, pos=0)
+        card2 = Card(name="Deleted Card", board_id=board.id, list_id=lst.id, pos=1)
+        db_session.add_all([card1, card2])
+        db_session.commit()
+
+        # Soft delete card2
+        card2.soft_delete()
+        db_session.commit()
+
+        # Get board
+        response = client.get(f"/api/boards/{board.id}", headers=auth_headers)
+        assert response.status_code == 200
+
+        data = response.get_json()
+        # Should only have 1 card (the active one)
+        assert len(data["lists"][0]["cards"]) == 1
+        assert data["lists"][0]["cards"][0]["name"] == "Active Card"
+
+    def test_get_board_filters_deleted_lists(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test that soft-deleted lists are filtered out from board response"""
+        # Create board with 2 lists
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.flush()
+
+        lst1 = List(name="To Do", board_id=board.id, pos=0)
+        lst2 = List(name="Deleted List", board_id=board.id, pos=1)
+        db_session.add_all([lst1, lst2])
+        db_session.commit()
+
+        # Soft delete lst2
+        lst2.soft_delete()
+        db_session.commit()
+
+        # Get board
+        response = client.get(f"/api/boards/{board.id}", headers=auth_headers)
+        assert response.status_code == 200
+
+        data = response.get_json()
+        # Should only have 1 list (the active one)
+        assert len(data["lists"]) == 1
+        assert data["lists"][0]["name"] == "To Do"
+
+    def test_get_board_filters_deleted_comments(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test that soft-deleted comments are filtered out from card response"""
+        # Create board, list, card and 2 comments
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.flush()
+
+        lst = List(name="To Do", board_id=board.id, pos=0)
+        db_session.add(lst)
+        db_session.flush()
+
+        card = Card(name="Test Card", board_id=board.id, list_id=lst.id, pos=0)
+        db_session.add(card)
+        db_session.flush()
+
+        comment1 = Comment(
+            text="Active comment", card_id=card.id, user_id=regular_user.id
+        )
+        comment2 = Comment(
+            text="Deleted comment", card_id=card.id, user_id=regular_user.id
+        )
+        db_session.add_all([comment1, comment2])
+        db_session.commit()
+
+        # Soft delete comment2
+        comment2.soft_delete()
+        db_session.commit()
+
+        # Get board
+        response = client.get(f"/api/boards/{board.id}", headers=auth_headers)
+        assert response.status_code == 200
+
+        data = response.get_json()
+        # Should only have 1 comment (the active one)
+        assert len(data["lists"][0]["cards"][0]["comments"]) == 1
+        assert data["lists"][0]["cards"][0]["comments"][0]["text"] == "Active comment"
+
+    def test_get_board_filters_deleted_checklists(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test that soft-deleted checklists are filtered out from card response"""
+        # Create board, list, card and 2 checklists
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.flush()
+
+        lst = List(name="To Do", board_id=board.id, pos=0)
+        db_session.add(lst)
+        db_session.flush()
+
+        card = Card(name="Test Card", board_id=board.id, list_id=lst.id, pos=0)
+        db_session.add(card)
+        db_session.flush()
+
+        checklist1 = Checklist(
+            name="Active Checklist", board_id=board.id, card_id=card.id, pos=0
+        )
+        checklist2 = Checklist(
+            name="Deleted Checklist", board_id=board.id, card_id=card.id, pos=1
+        )
+        db_session.add_all([checklist1, checklist2])
+        db_session.commit()
+
+        # Soft delete checklist2
+        checklist2.soft_delete()
+        db_session.commit()
+
+        # Get board
+        response = client.get(f"/api/boards/{board.id}", headers=auth_headers)
+        assert response.status_code == 200
+
+        data = response.get_json()
+        # Should only have 1 checklist (the active one)
+        assert len(data["lists"][0]["cards"][0]["checklists"]) == 1
+        assert (
+            data["lists"][0]["cards"][0]["checklists"][0]["name"] == "Active Checklist"
+        )
+
+    def test_get_board_filters_deleted_check_items(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test that soft-deleted check items are
+        filtered out from checklist response"""
+        # Create board, list, card, checklist and 2 check items
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.flush()
+
+        lst = List(name="To Do", board_id=board.id, pos=0)
+        db_session.add(lst)
+        db_session.flush()
+
+        card = Card(name="Test Card", board_id=board.id, list_id=lst.id, pos=0)
+        db_session.add(card)
+        db_session.flush()
+
+        checklist = Checklist(name="Tasks", board_id=board.id, card_id=card.id, pos=0)
+        db_session.add(checklist)
+        db_session.flush()
+
+        item1 = CheckItem(name="Active Task", checklist_id=checklist.id, pos=0)
+        item2 = CheckItem(name="Deleted Task", checklist_id=checklist.id, pos=1)
+        db_session.add_all([item1, item2])
+        db_session.commit()
+
+        # Soft delete item2
+        item2.soft_delete()
+        db_session.commit()
+
+        # Get board
+        response = client.get(f"/api/boards/{board.id}", headers=auth_headers)
+        assert response.status_code == 200
+
+        data = response.get_json()
+        # Should only have 1 check item (the active one)
+        assert len(data["lists"][0]["cards"][0]["checklists"][0]["items"]) == 1
+        assert (
+            data["lists"][0]["cards"][0]["checklists"][0]["items"][0]["name"]
+            == "Active Task"
+        )
+
+    def test_get_board_filters_deleted_card_labels(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test that soft-deleted card-label associations are filtered out"""
+        # Create board, list, card, label and 2 card-label associations
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.flush()
+
+        lst = List(name="To Do", board_id=board.id, pos=0)
+        db_session.add(lst)
+        db_session.flush()
+
+        card = Card(name="Test Card", board_id=board.id, list_id=lst.id, pos=0)
+        db_session.add(card)
+        db_session.flush()
+
+        label1 = Label(name="Urgent", color="red", board_id=board.id)
+        label2 = Label(name="Important", color="yellow", board_id=board.id)
+        db_session.add_all([label1, label2])
+        db_session.flush()
+
+        card_label1 = CardLabel(card_id=card.id, label_id=label1.id)
+        card_label2 = CardLabel(card_id=card.id, label_id=label2.id)
+        db_session.add_all([card_label1, card_label2])
+        db_session.commit()
+
+        # Soft delete card_label2
+        card_label2.soft_delete()
+        db_session.commit()
+
+        # Get board
+        response = client.get(f"/api/boards/{board.id}", headers=auth_headers)
+        assert response.status_code == 200
+
+        data = response.get_json()
+        # Should only have 1 label (the active one)
+        assert len(data["lists"][0]["cards"][0]["labels"]) == 1
+        assert data["lists"][0]["cards"][0]["labels"][0]["name"] == "Urgent"
+
+    def test_get_board_comprehensive_soft_delete_filtering(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test comprehensive soft delete filtering across all nested resources"""
+        # Create board with all types of nested resources, some deleted
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.flush()
+
+        # Active list
+        lst1 = List(name="Active List", board_id=board.id, pos=0)
+        db_session.add(lst1)
+        db_session.flush()
+
+        card1 = Card(name="Active Card 1", board_id=board.id, list_id=lst1.id, pos=0)
+        card2 = Card(name="Deleted Card", board_id=board.id, list_id=lst1.id, pos=1)
+        db_session.add_all([card1, card2])
+        db_session.flush()
+
+        # Active comment
+        comment1 = Comment(
+            text="Active comment", card_id=card1.id, user_id=regular_user.id
+        )
+        # Deleted comment
+        comment2 = Comment(
+            text="Deleted comment", card_id=card1.id, user_id=regular_user.id
+        )
+        db_session.add_all([comment1, comment2])
+        db_session.flush()
+
+        # Active checklist
+        checklist1 = Checklist(
+            name="Active Checklist", board_id=board.id, card_id=card1.id, pos=0
+        )
+        # Deleted checklist
+        checklist2 = Checklist(
+            name="Deleted Checklist", board_id=board.id, card_id=card1.id, pos=1
+        )
+        db_session.add_all([checklist1, checklist2])
+        db_session.flush()
+
+        # Active check item
+        item1 = CheckItem(name="Active Task", checklist_id=checklist1.id, pos=0)
+        # Deleted check item
+        item2 = CheckItem(name="Deleted Task", checklist_id=checklist1.id, pos=1)
+        db_session.add_all([item1, item2])
+        db_session.flush()
+
+        # Labels
+        label1 = Label(name="Active Label", color="red", board_id=board.id)
+        label2 = Label(name="Deleted Label", color="yellow", board_id=board.id)
+        db_session.add_all([label1, label2])
+        db_session.flush()
+
+        # Active card-label
+        card_label1 = CardLabel(card_id=card1.id, label_id=label1.id)
+        # Deleted card-label
+        card_label2 = CardLabel(card_id=card1.id, label_id=label2.id)
+        db_session.add_all([card_label1, card_label2])
+        db_session.commit()
+
+        # Soft delete some resources
+        card2.soft_delete()
+        comment2.soft_delete()
+        checklist2.soft_delete()
+        item2.soft_delete()
+        card_label2.soft_delete()
+        db_session.commit()
+
+        # Get board
+        response = client.get(f"/api/boards/{board.id}", headers=auth_headers)
+        assert response.status_code == 200
+
+        data = response.get_json()
+
+        # Verify lists: should have 1 list (we didn't delete the list)
+        assert len(data["lists"]) == 1
+        assert data["lists"][0]["name"] == "Active List"
+
+        # Verify cards: should have 1 card (card2 is deleted)
+        assert len(data["lists"][0]["cards"]) == 1
+        assert data["lists"][0]["cards"][0]["name"] == "Active Card 1"
+
+        # Verify comments: should have 1 comment (comment2 is deleted)
+        assert len(data["lists"][0]["cards"][0]["comments"]) == 1
+        assert data["lists"][0]["cards"][0]["comments"][0]["text"] == "Active comment"
+
+        # Verify checklists: should have 1 checklist (checklist2 is deleted)
+        assert len(data["lists"][0]["cards"][0]["checklists"]) == 1
+        assert (
+            data["lists"][0]["cards"][0]["checklists"][0]["name"] == "Active Checklist"
+        )
+
+        # Verify check items: should have 1 item (item2 is deleted)
+        assert len(data["lists"][0]["cards"][0]["checklists"][0]["items"]) == 1
+        assert (
+            data["lists"][0]["cards"][0]["checklists"][0]["items"][0]["name"]
+            == "Active Task"
+        )
+
+        # Verify labels: should have 1 label (card_label2 is deleted)
+        assert len(data["lists"][0]["cards"][0]["labels"]) == 1
+        assert data["lists"][0]["cards"][0]["labels"][0]["name"] == "Active Label"
diff --git a/backend/tests/routes/test_cards.py b/backend/tests/routes/test_cards.py
index 1c05c20..f250d4e 100644
--- a/backend/tests/routes/test_cards.py
+++ b/backend/tests/routes/test_cards.py
@@ -160,7 +160,8 @@ class TestCardRoutes:
 
         # Verify card is deleted
         deleted_card = db.session.get(Card, card.id)
-        assert deleted_card is None
+        assert deleted_card is not None
+        assert deleted_card.status == "deleted"
 
     def test_delete_card_not_found(self, client, db_session, auth_headers):
         """Test deleting a non-existent card"""
@@ -168,6 +169,38 @@ class TestCardRoutes:
 
         assert response.status_code == 404
 
+    def test_get_soft_deleted_card_returns_404(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test that getting a soft-deleted card returns 404"""
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.flush()
+
+        lst = List(name="To Do", board_id=board.id, pos=0)
+        db_session.add(lst)
+        db_session.flush()
+
+        card = Card(name="To Delete", board_id=board.id, list_id=lst.id, pos=0)
+        db_session.add(card)
+        db_session.commit()
+
+        # Soft delete the card
+        card.soft_delete()
+        db_session.commit()
+
+        # Verify card is deleted in database
+        deleted_card = db.session.get(Card, card.id)
+        assert deleted_card is not None
+        assert deleted_card.status == "deleted"
+        assert deleted_card.deleted_at is not None
+
+        # Try to get the deleted card via API
+        response = client.get(f"/api/cards/{card.id}", headers=auth_headers)
+
+        # Should return 404
+        assert response.status_code == 404
+
     def test_update_card_position_within_same_list(
         self, client, db_session, regular_user, auth_headers
     ):
diff --git a/backend/tests/routes/test_checklists.py b/backend/tests/routes/test_checklists.py
index 373f2c0..989c915 100644
--- a/backend/tests/routes/test_checklists.py
+++ b/backend/tests/routes/test_checklists.py
@@ -245,7 +245,8 @@ class TestChecklistRoutes:
 
         # Verify checklist is deleted
         deleted_checklist = db.session.get(Checklist, checklist.id)
-        assert deleted_checklist is None
+        assert deleted_checklist is not None
+        assert deleted_checklist.status == "deleted"
 
     def test_delete_checklist_not_found(self, client, db_session, auth_headers):
         """Test deleting a non-existent checklist"""
@@ -287,7 +288,8 @@ class TestChecklistRoutes:
 
         # Verify check item is deleted
         deleted_item = db.session.get(CheckItem, item.id)
-        assert deleted_item is None
+        assert deleted_item is not None
+        assert deleted_item.status == "deleted"
 
     def test_delete_check_item_not_found(self, client, db_session, auth_headers):
         """Test deleting a non-existent check item"""
diff --git a/backend/tests/routes/test_comments.py b/backend/tests/routes/test_comments.py
index fc8160e..2b5d54d 100644
--- a/backend/tests/routes/test_comments.py
+++ b/backend/tests/routes/test_comments.py
@@ -196,7 +196,8 @@ class TestCommentRoutes:
 
         # Verify comment is deleted
         deleted_comment = db.session.get(Comment, comment.id)
-        assert deleted_comment is None
+        assert deleted_comment is not None
+        assert deleted_comment.status == "deleted"
 
     def test_delete_comment_not_found(self, client, db_session, auth_headers):
         """Test deleting a non-existent comment"""
diff --git a/backend/tests/routes/test_epics.py b/backend/tests/routes/test_epics.py
index f137ce3..bd03689 100644
--- a/backend/tests/routes/test_epics.py
+++ b/backend/tests/routes/test_epics.py
@@ -416,7 +416,8 @@ class TestEpicRoutes:
 
         # Verify epic is deleted
         deleted_epic = db.session.get(Epic, epic_id)
-        assert deleted_epic is None
+        assert deleted_epic is not None
+        assert deleted_epic.status == "deleted"
 
     def test_delete_epic_with_cards(
         self, client, db_session, auth_headers, test_board, test_card
diff --git a/backend/tests/routes/test_labels.py b/backend/tests/routes/test_labels.py
index 2216757..b4e653a 100644
--- a/backend/tests/routes/test_labels.py
+++ b/backend/tests/routes/test_labels.py
@@ -181,4 +181,5 @@ class TestLabelRoutes:
             .filter_by(card_id=card.id, label_id=label.id)
             .first()
         )
-        assert deleted_card_label is None
+        assert deleted_card_label is not None
+        assert deleted_card_label.status == "deleted"
diff --git a/backend/tests/routes/test_lists.py b/backend/tests/routes/test_lists.py
index dcb8e4f..0c321ad 100644
--- a/backend/tests/routes/test_lists.py
+++ b/backend/tests/routes/test_lists.py
@@ -116,7 +116,8 @@ class TestListRoutes:
 
         # Verify list is deleted
         deleted_list = db.session.get(List, lst.id)
-        assert deleted_list is None
+        assert deleted_list is not None
+        assert deleted_list.status == "deleted"
 
     def test_delete_list_not_found(self, client, db_session, auth_headers):
         """Test deleting a non-existent list"""
@@ -144,11 +145,13 @@ class TestListRoutes:
 
         assert response.status_code == 200
 
-        # Verify both list and card are deleted
+        # Verify both list and card are soft-deleted
         deleted_list = db.session.get(List, lst.id)
         deleted_card = db.session.get(Card, card.id)
-        assert deleted_list is None
-        assert deleted_card is None
+        assert deleted_list is not None
+        assert deleted_list.status == "deleted"
+        assert deleted_card is not None
+        assert deleted_card.status == "deleted"
 
     def test_update_list_position_reorders_others(
         self, client, db_session, regular_user, auth_headers
diff --git a/backend/tests/routes/test_soft_delete_integration.py b/backend/tests/routes/test_soft_delete_integration.py
new file mode 100644
index 0000000..828c16a
--- /dev/null
+++ b/backend/tests/routes/test_soft_delete_integration.py
@@ -0,0 +1,496 @@
+"""High-level integration tests for soft delete functionality
+
+These tests verify that soft delete works correctly by checking:
+1. The delete endpoint returns success
+2. The record is marked as deleted in the database (deleted_at is set)
+3. The record still exists (soft delete, not hard delete)
+"""
+
+import pytest
+
+from app import db
+from app.models import (Board, Card, CardLabel, CardLink, CheckItem, Checklist,
+                        Comment, Epic, Label, List, Wiki)
+
+
+@pytest.mark.integration
+class TestSoftDeleteIntegration:
+    """High-level integration tests for soft delete across all resources"""
+
+    def test_soft_delete_card_marks_deleted(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test that deleting a card marks it as deleted in the database"""
+        # Create board, list and card
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.flush()
+
+        lst = List(name="To Do", board_id=board.id, pos=0)
+        db_session.add(lst)
+        db_session.flush()
+
+        card = Card(name="Test Card", board_id=board.id, list_id=lst.id, pos=0)
+        db_session.add(card)
+        db_session.commit()
+
+        # Delete the card
+        response = client.delete(f"/api/cards/{card.id}", headers=auth_headers)
+        assert response.status_code == 200
+
+        # Verify card is marked as deleted in database
+        deleted_card = db.session.get(Card, card.id)
+        assert deleted_card is not None
+        assert deleted_card.deleted_at is not None
+
+    def test_soft_delete_list_marks_deleted(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test that deleting a list marks it as deleted in the database"""
+        # Create board and list
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.flush()
+
+        lst = List(name="To Do", board_id=board.id, pos=0)
+        db_session.add(lst)
+        db_session.commit()
+
+        # Delete the list
+        response = client.delete(f"/api/lists/{lst.id}", headers=auth_headers)
+        assert response.status_code == 200
+
+        # Verify list is marked as deleted in database
+        deleted_list = db.session.get(List, lst.id)
+        assert deleted_list is not None
+        assert deleted_list.deleted_at is not None
+
+    def test_soft_delete_comment_marks_deleted(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test that deleting a comment marks it as deleted in the database"""
+        # Create board, list, card and comment
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.flush()
+
+        lst = List(name="To Do", board_id=board.id, pos=0)
+        db_session.add(lst)
+        db_session.flush()
+
+        card = Card(name="Test Card", board_id=board.id, list_id=lst.id, pos=0)
+        db_session.add(card)
+        db_session.flush()
+
+        comment = Comment(text="Test comment", card_id=card.id, user_id=regular_user.id)
+        db_session.add(comment)
+        db_session.commit()
+
+        # Delete the comment
+        response = client.delete(f"/api/comments/{comment.id}", headers=auth_headers)
+        assert response.status_code == 200
+
+        # Verify comment is marked as deleted in database
+        deleted_comment = db.session.get(Comment, comment.id)
+        assert deleted_comment is not None
+        assert deleted_comment.deleted_at is not None
+
+    def test_soft_delete_checklist_marks_deleted(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test that deleting a checklist marks it as deleted in the database"""
+        # Create board, list, card and checklist
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.flush()
+
+        lst = List(name="To Do", board_id=board.id, pos=0)
+        db_session.add(lst)
+        db_session.flush()
+
+        card = Card(name="Test Card", board_id=board.id, list_id=lst.id, pos=0)
+        db_session.add(card)
+        db_session.flush()
+
+        checklist = Checklist(name="Tasks", board_id=board.id, card_id=card.id, pos=0)
+        db_session.add(checklist)
+        db_session.commit()
+
+        # Delete the checklist
+        response = client.delete(
+            f"/api/checklists/{checklist.id}", headers=auth_headers
+        )
+        assert response.status_code == 200
+
+        # Verify checklist is marked as deleted in database
+        deleted_checklist = db.session.get(Checklist, checklist.id)
+        assert deleted_checklist is not None
+        assert deleted_checklist.deleted_at is not None
+
+    def test_soft_delete_check_item_marks_deleted(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test that deleting a check item marks it as deleted in the database"""
+        # Create board, list, card, checklist and check item
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.flush()
+
+        lst = List(name="To Do", board_id=board.id, pos=0)
+        db_session.add(lst)
+        db_session.flush()
+
+        card = Card(name="Test Card", board_id=board.id, list_id=lst.id, pos=0)
+        db_session.add(card)
+        db_session.flush()
+
+        checklist = Checklist(name="Tasks", board_id=board.id, card_id=card.id, pos=0)
+        db_session.add(checklist)
+        db_session.flush()
+
+        item = CheckItem(
+            name="Task", checklist_id=checklist.id, pos=0, state="incomplete"
+        )
+        db_session.add(item)
+        db_session.commit()
+
+        # Delete the check item
+        response = client.delete(f"/api/check-items/{item.id}", headers=auth_headers)
+        assert response.status_code == 200
+
+        # Verify check item is marked as deleted in database
+        deleted_item = db.session.get(CheckItem, item.id)
+        assert deleted_item is not None
+        assert deleted_item.deleted_at is not None
+
+    def test_soft_delete_card_label_marks_deleted(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test that removing a label from a card marks the association as deleted"""
+        # Create board, list, card and labels
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.flush()
+
+        lst = List(name="To Do", board_id=board.id, pos=0)
+        db_session.add(lst)
+        db_session.flush()
+
+        card = Card(name="Test Card", board_id=board.id, list_id=lst.id, pos=0)
+        db_session.add(card)
+        db_session.flush()
+
+        label = Label(name="Urgent", color="red", board_id=board.id)
+        db_session.add(label)
+        db_session.flush()
+
+        card_label = CardLabel(card_id=card.id, label_id=label.id)
+        db_session.add(card_label)
+        db_session.commit()
+
+        # Remove label from card
+        response = client.delete(
+            f"/api/cards/{card.id}/labels/{label.id}", headers=auth_headers
+        )
+        assert response.status_code == 200
+
+        # Verify card-label association is marked as deleted in database
+        deleted_card_label = (
+            db_session.query(CardLabel)
+            .filter_by(card_id=card.id, label_id=label.id)
+            .first()
+        )
+        assert deleted_card_label is not None
+        assert deleted_card_label.deleted_at is not None
+
+    def test_soft_delete_epic_marks_deleted(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test that deleting an epic marks it as deleted in the database"""
+        # Create board and epic
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.flush()
+
+        epic = Epic(name="Test Epic", board_id=board.id, color="#3b82f6")
+        db_session.add(epic)
+        db_session.commit()
+
+        # Delete the epic
+        response = client.delete(f"/api/epics/{epic.id}", headers=auth_headers)
+        assert response.status_code == 200
+
+        # Verify epic is marked as deleted in database
+        deleted_epic = db.session.get(Epic, epic.id)
+        assert deleted_epic is not None
+        assert deleted_epic.deleted_at is not None
+
+    def test_soft_delete_epic_unlinks_card(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test that soft-deleting an epic unlinks associated cards"""
+        # Create board, list, card and epic
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.flush()
+
+        lst = List(name="To Do", board_id=board.id, pos=0)
+        db_session.add(lst)
+        db_session.flush()
+
+        card = Card(name="Test Card", board_id=board.id, list_id=lst.id, pos=0)
+        db_session.add(card)
+        db_session.flush()
+
+        epic = Epic(name="Test Epic", board_id=board.id, color="#3b82f6")
+        db_session.add(epic)
+        db_session.flush()
+
+        card.epic_id = epic.id
+        db_session.commit()
+
+        # Delete epic
+        response = client.delete(f"/api/epics/{epic.id}", headers=auth_headers)
+        assert response.status_code == 200
+
+        # Verify card no longer has epic
+        db.session.refresh(card)
+        assert card.epic_id is None
+
+    def test_soft_delete_wiki_marks_deleted(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test that deleting a wiki marks it as deleted in the database"""
+        # Create board and wiki
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.flush()
+
+        wiki = Wiki(
+            name="Test Wiki",
+            board_id=board.id,
+            slug="test-wiki",
+            content=[{"type": "paragraph", "children": [{"text": "Content"}]}],
+            created_by=regular_user.id,
+        )
+        db_session.add(wiki)
+        db_session.commit()
+
+        # Delete the wiki
+        response = client.delete(f"/api/wikis/{wiki.id}", headers=auth_headers)
+        assert response.status_code == 200
+
+        # Verify wiki is marked as deleted in database
+        deleted_wiki = db.session.get(Wiki, wiki.id)
+        assert deleted_wiki is not None
+        assert deleted_wiki.deleted_at is not None
+
+    def test_soft_delete_board_marks_deleted(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test that deleting a board marks it as deleted in the database"""
+        # Create board
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.commit()
+
+        # Delete the board
+        response = client.delete(f"/api/boards/{board.id}", headers=auth_headers)
+        assert response.status_code == 200
+
+        # Verify board is marked as deleted in database
+        deleted_board = db.session.get(Board, board.id)
+        assert deleted_board is not None
+        assert deleted_board.status == "deleted"
+
+    def test_soft_delete_card_link_marks_deleted(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test that deleting a card link marks it as deleted in the database"""
+        # Create board, list and cards
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.flush()
+
+        lst = List(name="To Do", board_id=board.id, pos=0)
+        db_session.add(lst)
+        db_session.flush()
+
+        parent_card = Card(name="Parent Card", board_id=board.id, list_id=lst.id, pos=0)
+        child_card = Card(name="Child Card", board_id=board.id, list_id=lst.id, pos=1)
+        db_session.add_all([parent_card, child_card])
+        db_session.commit()
+
+        # Create card link
+        link = CardLink(
+            parent_card_id=parent_card.id,
+            child_card_id=child_card.id,
+            created_by=regular_user.id,
+        )
+        db_session.add(link)
+        db_session.commit()
+
+        # Delete the link
+        response = client.delete(f"/api/card-links/{link.id}", headers=auth_headers)
+        assert response.status_code == 200
+
+        # Verify link is marked as deleted in database
+        deleted_link = db.session.get(CardLink, link.id)
+        assert deleted_link is not None
+        assert deleted_link.deleted_at is not None
+
+    def test_soft_delete_cascade_from_list_to_cards(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test that deleting a list soft-deletes its cards"""
+        # Create board, list and cards
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.flush()
+
+        lst = List(name="To Do", board_id=board.id, pos=0)
+        db_session.add(lst)
+        db_session.flush()
+
+        card1 = Card(name="Card 1", board_id=board.id, list_id=lst.id, pos=0)
+        card2 = Card(name="Card 2", board_id=board.id, list_id=lst.id, pos=1)
+        db_session.add_all([card1, card2])
+        db_session.commit()
+
+        # Delete list
+        response = client.delete(f"/api/lists/{lst.id}", headers=auth_headers)
+        assert response.status_code == 200
+
+        # Verify list is soft-deleted
+        deleted_list = db.session.get(List, lst.id)
+        assert deleted_list is not None
+        assert deleted_list.deleted_at is not None
+
+        # Verify cards are also soft-deleted
+        deleted_card1 = db.session.get(Card, card1.id)
+        deleted_card2 = db.session.get(Card, card2.id)
+        assert deleted_card1 is not None
+        assert deleted_card1.deleted_at is not None
+        assert deleted_card2 is not None
+        assert deleted_card2.deleted_at is not None
+
+    def test_soft_delete_multiple_resources_in_sequence(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test deleting multiple resources in sequence and verifying soft delete"""
+        # Create board with lists, cards, comments, checklists, labels
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.flush()
+
+        lst = List(name="To Do", board_id=board.id, pos=0)
+        db_session.add(lst)
+        db_session.flush()
+
+        card = Card(name="Test Card", board_id=board.id, list_id=lst.id, pos=0)
+        db_session.add(card)
+        db_session.flush()
+
+        comment = Comment(text="Test comment", card_id=card.id, user_id=regular_user.id)
+        db_session.add(comment)
+        db_session.flush()
+
+        label = Label(name="Urgent", color="red", board_id=board.id)
+        db_session.add(label)
+        db_session.flush()
+
+        card_label = CardLabel(card_id=card.id, label_id=label.id)
+        db_session.add(card_label)
+        db_session.flush()
+
+        checklist = Checklist(name="Tasks", board_id=board.id, card_id=card.id, pos=0)
+        db_session.add(checklist)
+        db_session.flush()
+
+        item = CheckItem(
+            name="Task", checklist_id=checklist.id, pos=0, state="incomplete"
+        )
+        db_session.add(item)
+        db_session.commit()
+
+        # Delete multiple resources in sequence
+        client.delete(f"/api/comments/{comment.id}", headers=auth_headers)
+        client.delete(f"/api/check-items/{item.id}", headers=auth_headers)
+        client.delete(f"/api/cards/{card.id}/labels/{label.id}", headers=auth_headers)
+
+        # Verify all are marked as deleted in database
+        deleted_comment = db.session.get(Comment, comment.id)
+        deleted_item = db.session.get(CheckItem, item.id)
+        deleted_card_label = (
+            db_session.query(CardLabel)
+            .filter_by(card_id=card.id, label_id=label.id)
+            .first()
+        )
+
+        assert deleted_comment is not None
+        assert deleted_comment.deleted_at is not None
+
+        assert deleted_item is not None
+        assert deleted_item.deleted_at is not None
+
+        assert deleted_card_label is not None
+        assert deleted_card_label.deleted_at is not None
+
+    def test_soft_delete_record_still_exists(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test that soft-deleted records still exist in the database"""
+        # Create board
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.commit()
+
+        # Delete the board
+        response = client.delete(f"/api/boards/{board.id}", headers=auth_headers)
+        assert response.status_code == 200
+
+        # Verify record still exists (not hard deleted)
+        deleted_board = db.session.get(Board, board.id)
+        assert deleted_board is not None
+        assert deleted_board.id == board.id
+        assert deleted_board.name == "Test Board"
+
+    def test_convert_check_item_to_card_deletes_check_item(
+        self, client, db_session, regular_user, auth_headers
+    ):
+        """Test that converting a check item to a card soft-deletes the check item"""
+        # Create board, list, card, checklist and check item
+        board = Board(name="Test Board", user_id=regular_user.id)
+        db_session.add(board)
+        db_session.flush()
+
+        lst = List(name="To Do", board_id=board.id, pos=0)
+        db_session.add(lst)
+        db_session.flush()
+
+        card = Card(name="Parent Card", board_id=board.id, list_id=lst.id, pos=0)
+        db_session.add(card)
+        db_session.flush()
+
+        checklist = Checklist(name="Tasks", board_id=board.id, card_id=card.id, pos=0)
+        db_session.add(checklist)
+        db_session.flush()
+
+        item = CheckItem(
+            name="Task to convert", checklist_id=checklist.id, pos=0, state="incomplete"
+        )
+        db_session.add(item)
+        db_session.commit()
+
+        # Convert check item to card
+        response = client.post(
+            f"/api/cards/{card.id}/checklist-items/{item.id}/convert-to-card",
+            headers=auth_headers,
+            json={"list_id": lst.id},
+        )
+        assert response.status_code == 201
+
+        # Verify check item is soft-deleted
+        deleted_item = db.session.get(CheckItem, item.id)
+        assert deleted_item is not None
+        assert deleted_item.deleted_at is not None
diff --git a/backend/tests/routes/test_wikis.py b/backend/tests/routes/test_wikis.py
index 3603d2b..fe0f16e 100644
--- a/backend/tests/routes/test_wikis.py
+++ b/backend/tests/routes/test_wikis.py
@@ -518,12 +518,13 @@ class TestWikiRoutes:
 
         # Verify wiki is deleted
         deleted_wiki = db.session.get(Wiki, wiki_id)
-        assert deleted_wiki is None
+        assert deleted_wiki is not None
+        assert deleted_wiki.status == "deleted"
 
     def test_delete_wiki_with_links(
         self, client, db_session, auth_headers, test_board, regular_user, test_card
     ):
-        """Test deleting wiki removes entity links"""
+        """Test deleting wiki (soft delete) preserves entity links"""
         wiki = Wiki(
             name="Wiki with Links",
             board_id=test_board.id,
@@ -545,13 +546,18 @@ class TestWikiRoutes:
 
         assert response.status_code == 200
 
-        # Verify links are deleted (cascade)
+        # Verify wiki is soft-deleted
+        deleted_wiki = db.session.get(Wiki, wiki.id)
+        assert deleted_wiki is not None
+        assert deleted_wiki.status == "deleted"
+
+        # Verify links are preserved (not deleted with soft delete)
         from sqlalchemy import select
 
         links = db.session.scalars(
             select(wiki_entity_links).where(wiki_entity_links.c.wiki_id == wiki.id)
         ).all()
-        assert len(links) == 0
+        assert len(links) == 1  # Links are preserved
 
     def test_delete_wiki_not_found(self, client, db_session, auth_headers):
         """Test deleting non-existent wiki"""