diff --git a/.env b/.env
index e37607b3..b4e90386 100644
--- a/.env
+++ b/.env
@@ -1,8 +1,9 @@
 # .env.example
 
-    PROJECT_NAME: str = "Ecommerce Backend API with Marketplace Support"
-    DESCRIPTION: str = "Advanced product management system with JWT authentication"
-    VERSION: str = "0.0.1"
+# Project information
+PROJECT_NAME=Ecommerce Backend API with Marketplace Support
+DESCRIPTION=Advanced product management system with JWT authentication
+VERSION=0.0.1
 
 # Database Configuration
 # DATABASE_URL=postgresql://username:password@localhost:5432/ecommerce_db
diff --git a/app/api/main.py b/app/api/main.py
index 0cbc0f7f..bf6fc98a 100644
--- a/app/api/main.py
+++ b/app/api/main.py
@@ -1,13 +1,13 @@
 from fastapi import APIRouter
-from app.api.v1 import auth, products, stock, shops, marketplace, admin, stats
+from app.api.v1 import auth, product, stock, shop, marketplace, admin, stats
 
 api_router = APIRouter()
 
 # Include all route modules
 api_router.include_router(auth.router, prefix="/auth", tags=["authentication"])
-api_router.include_router(products.router, prefix="/products", tags=["products"])
+api_router.include_router(product.router, prefix="/product", tags=["product"])
 api_router.include_router(stock.router, prefix="/stock", tags=["stock"])
-api_router.include_router(shops.router, prefix="/shops", tags=["shops"])
+api_router.include_router(shop.router, prefix="/shop", tags=["shop"])
 api_router.include_router(marketplace.router, prefix="/marketplace", tags=["marketplace"])
 api_router.include_router(admin.router, prefix="/admin", tags=["admin"])
 api_router.include_router(stats.router, prefix="/stats", tags=["statistics"])
diff --git a/app/api/v1/admin.py b/app/api/v1/admin.py
index c5197d39..0847c086 100644
--- a/app/api/v1/admin.py
+++ b/app/api/v1/admin.py
@@ -1,14 +1,13 @@
 from typing import List, Optional
 
-from fastapi import APIRouter, Depends, HTTPException, Query, BackgroundTasks
+from fastapi import APIRouter, Depends, HTTPException, Query
 from sqlalchemy.orm import Session
 from app.core.database import get_db
-from app.api.deps import get_current_user, get_current_admin_user
-from app.tasks.background_tasks import process_marketplace_import
+from app.api.deps import get_current_admin_user
+from app.services.admin_service import admin_service
 from middleware.decorators import rate_limit
-from models.api_models import MarketplaceImportJobResponse, MarketplaceImportRequest, UserResponse, ShopListResponse
-from models.database_models import User, MarketplaceImportJob, Shop
-from datetime import datetime
+from models.api_models import MarketplaceImportJobResponse, UserResponse, ShopListResponse
+from models.database_models import User
 import logging
 
 router = APIRouter()
@@ -24,8 +23,12 @@ def get_all_users(
         current_admin: User = Depends(get_current_admin_user)
 ):
     """Get all users (Admin only)"""
-    users = db.query(User).offset(skip).limit(limit).all()
-    return [UserResponse.model_validate(user) for user in users]
+    try:
+        users = admin_service.get_all_users(db=db, skip=skip, limit=limit)
+        return [UserResponse.model_validate(user) for user in users]
+    except Exception as e:
+        logger.error(f"Error getting users: {str(e)}")
+        raise HTTPException(status_code=500, detail="Internal server error")
 
 
 @router.put("/admin/users/{user_id}/status")
@@ -35,20 +38,14 @@ def toggle_user_status(
         current_admin: User = Depends(get_current_admin_user)
 ):
     """Toggle user active status (Admin only)"""
-    user = db.query(User).filter(User.id == user_id).first()
-    if not user:
-        raise HTTPException(status_code=404, detail="User not found")
-
-    if user.id == current_admin.id:
-        raise HTTPException(status_code=400, detail="Cannot deactivate your own account")
-
-    user.is_active = not user.is_active
-    user.updated_at = datetime.utcnow()
-    db.commit()
-    db.refresh(user)
-
-    status = "activated" if user.is_active else "deactivated"
-    return {"message": f"User {user.username} has been {status}"}
+    try:
+        user, message = admin_service.toggle_user_status(db, user_id, current_admin.id)
+        return {"message": message}
+    except HTTPException:
+        raise
+    except Exception as e:
+        logger.error(f"Error toggling user {user_id} status: {str(e)}")
+        raise HTTPException(status_code=500, detail="Internal server error")
 
 
 @router.get("/admin/shops", response_model=ShopListResponse)
@@ -59,15 +56,18 @@ def get_all_shops_admin(
         current_admin: User = Depends(get_current_admin_user)
 ):
     """Get all shops with admin view (Admin only)"""
-    total = db.query(Shop).count()
-    shops = db.query(Shop).offset(skip).limit(limit).all()
+    try:
+        shops, total = admin_service.get_all_shops(db=db, skip=skip, limit=limit)
 
-    return ShopListResponse(
-        shops=shops,
-        total=total,
-        skip=skip,
-        limit=limit
-    )
+        return ShopListResponse(
+            shops=shops,
+            total=total,
+            skip=skip,
+            limit=limit
+        )
+    except Exception as e:
+        logger.error(f"Error getting shops: {str(e)}")
+        raise HTTPException(status_code=500, detail="Internal server error")
 
 
 @router.put("/admin/shops/{shop_id}/verify")
@@ -77,17 +77,14 @@ def verify_shop(
         current_admin: User = Depends(get_current_admin_user)
 ):
     """Verify/unverify shop (Admin only)"""
-    shop = db.query(Shop).filter(Shop.id == shop_id).first()
-    if not shop:
-        raise HTTPException(status_code=404, detail="Shop not found")
-
-    shop.is_verified = not shop.is_verified
-    shop.updated_at = datetime.utcnow()
-    db.commit()
-    db.refresh(shop)
-
-    status = "verified" if shop.is_verified else "unverified"
-    return {"message": f"Shop {shop.shop_code} has been {status}"}
+    try:
+        shop, message = admin_service.verify_shop(db, shop_id)
+        return {"message": message}
+    except HTTPException:
+        raise
+    except Exception as e:
+        logger.error(f"Error verifying shop {shop_id}: {str(e)}")
+        raise HTTPException(status_code=500, detail="Internal server error")
 
 
 @router.put("/admin/shops/{shop_id}/status")
@@ -97,17 +94,14 @@ def toggle_shop_status(
         current_admin: User = Depends(get_current_admin_user)
 ):
     """Toggle shop active status (Admin only)"""
-    shop = db.query(Shop).filter(Shop.id == shop_id).first()
-    if not shop:
-        raise HTTPException(status_code=404, detail="Shop not found")
-
-    shop.is_active = not shop.is_active
-    shop.updated_at = datetime.utcnow()
-    db.commit()
-    db.refresh(shop)
-
-    status = "activated" if shop.is_active else "deactivated"
-    return {"message": f"Shop {shop.shop_code} has been {status}"}
+    try:
+        shop, message = admin_service.toggle_shop_status(db, shop_id)
+        return {"message": message}
+    except HTTPException:
+        raise
+    except Exception as e:
+        logger.error(f"Error toggling shop {shop_id} status: {str(e)}")
+        raise HTTPException(status_code=500, detail="Internal server error")
 
 
 @router.get("/admin/marketplace-import-jobs", response_model=List[MarketplaceImportJobResponse])
@@ -121,33 +115,15 @@ def get_all_marketplace_import_jobs(
         current_admin: User = Depends(get_current_admin_user)
 ):
     """Get all marketplace import jobs (Admin only)"""
-
-    query = db.query(MarketplaceImportJob)
-
-    # Apply filters
-    if marketplace:
-        query = query.filter(MarketplaceImportJob.marketplace.ilike(f"%{marketplace}%"))
-    if shop_name:
-        query = query.filter(MarketplaceImportJob.shop_name.ilike(f"%{shop_name}%"))
-    if status:
-        query = query.filter(MarketplaceImportJob.status == status)
-
-    # Order by creation date and apply pagination
-    jobs = query.order_by(MarketplaceImportJob.created_at.desc()).offset(skip).limit(limit).all()
-
-    return [
-        MarketplaceImportJobResponse(
-            job_id=job.id,
-            status=job.status,
-            marketplace=job.marketplace,
-            shop_name=job.shop_name,
-            imported=job.imported_count or 0,
-            updated=job.updated_count or 0,
-            total_processed=job.total_processed or 0,
-            error_count=job.error_count or 0,
-            error_message=job.error_message,
-            created_at=job.created_at,
-            started_at=job.started_at,
-            completed_at=job.completed_at
-        ) for job in jobs
-    ]
+    try:
+        return admin_service.get_marketplace_import_jobs(
+            db=db,
+            marketplace=marketplace,
+            shop_name=shop_name,
+            status=status,
+            skip=skip,
+            limit=limit
+        )
+    except Exception as e:
+        logger.error(f"Error getting marketplace import jobs: {str(e)}")
+        raise HTTPException(status_code=500, detail="Internal server error")
diff --git a/app/api/v1/products.py b/app/api/v1/product.py
similarity index 95%
rename from app/api/v1/products.py
rename to app/api/v1/product.py
index 43d8c1f9..038f642d 100644
--- a/app/api/v1/products.py
+++ b/app/api/v1/product.py
@@ -19,7 +19,7 @@ logger = logging.getLogger(__name__)
 
 
 # Enhanced Product Routes with Marketplace Support
-@router.get("/products", response_model=ProductListResponse)
+@router.get("/product", response_model=ProductListResponse)
 def get_products(
         skip: int = Query(0, ge=0),
         limit: int = Query(100, ge=1, le=1000),
@@ -58,7 +58,7 @@ def get_products(
         raise HTTPException(status_code=500, detail="Internal server error")
 
 
-@router.post("/products", response_model=ProductResponse)
+@router.post("/product", response_model=ProductResponse)
 def create_product(
         product: ProductCreate,
         db: Session = Depends(get_db),
@@ -86,7 +86,7 @@ def create_product(
         raise HTTPException(status_code=500, detail="Internal server error")
 
 
-@router.get("/products/{product_id}", response_model=ProductDetailResponse)
+@router.get("/product/{product_id}", response_model=ProductDetailResponse)
 def get_product(
         product_id: str,
         db: Session = Depends(get_db),
@@ -116,7 +116,7 @@ def get_product(
         raise HTTPException(status_code=500, detail="Internal server error")
 
 
-@router.put("/products/{product_id}", response_model=ProductResponse)
+@router.put("/product/{product_id}", response_model=ProductResponse)
 def update_product(
         product_id: str,
         product_update: ProductUpdate,
@@ -142,7 +142,7 @@ def update_product(
         raise HTTPException(status_code=500, detail="Internal server error")
 
 
-@router.delete("/products/{product_id}")
+@router.delete("/product/{product_id}")
 def delete_product(
         product_id: str,
         db: Session = Depends(get_db),
diff --git a/app/api/v1/shops.py b/app/api/v1/shop.py
similarity index 100%
rename from app/api/v1/shops.py
rename to app/api/v1/shop.py
diff --git a/app/core/lifespan.py b/app/core/lifespan.py
index 76c4953a..cb7e5096 100644
--- a/app/core/lifespan.py
+++ b/app/core/lifespan.py
@@ -2,18 +2,21 @@ from contextlib import asynccontextmanager
 from fastapi import FastAPI
 from sqlalchemy import text
 from .logging import setup_logging
-from .database import engine
+from .database import engine, SessionLocal
 from models.database_models import Base
 import logging
+from middleware.auth import AuthManager
 
 logger = logging.getLogger(__name__)
+auth_manager = AuthManager()
+
 
 @asynccontextmanager
 async def lifespan(app: FastAPI):
     """Application lifespan events"""
     # Startup
-    logger = setup_logging()  # Configure logging first
-    logger.info("Starting up ecommerce API")
+    app_logger = setup_logging()  # Configure logging first
+    app_logger.info("Starting up ecommerce API")
 
     # Create tables
     Base.metadata.create_all(bind=engine)
@@ -21,10 +24,19 @@ async def lifespan(app: FastAPI):
     # Create indexes
     create_indexes()
 
+    # Create default admin user
+    db = SessionLocal()
+    try:
+        auth_manager.create_default_admin_user(db)
+    except Exception as e:
+        logger.error(f"Failed to create default admin user: {e}")
+    finally:
+        db.close()
+
     yield
 
     # Shutdown
-    logger.info("Shutting down ecommerce API")
+    app_logger.info("Shutting down ecommerce API")
 
 
 def create_indexes():
diff --git a/app/services/admin_service.py b/app/services/admin_service.py
new file mode 100644
index 00000000..5b0de6e1
--- /dev/null
+++ b/app/services/admin_service.py
@@ -0,0 +1,193 @@
+from sqlalchemy.orm import Session
+from sqlalchemy import func
+from fastapi import HTTPException
+from datetime import datetime
+import logging
+from typing import List, Optional, Tuple
+
+from models.database_models import User, MarketplaceImportJob, Shop
+from models.api_models import MarketplaceImportJobResponse
+
+logger = logging.getLogger(__name__)
+
+
+class AdminService:
+    """Service class for admin operations following the application's service pattern"""
+
+    def get_all_users(self, db: Session, skip: int = 0, limit: int = 100) -> List[User]:
+        """Get paginated list of all users"""
+        return db.query(User).offset(skip).limit(limit).all()
+
+    def toggle_user_status(self, db: Session, user_id: int, current_admin_id: int) -> Tuple[User, str]:
+        """
+        Toggle user active status
+
+        Args:
+            db: Database session
+            user_id: ID of user to toggle
+            current_admin_id: ID of the admin performing the action
+
+        Returns:
+            Tuple of (updated_user, status_message)
+
+        Raises:
+            HTTPException: If user not found or trying to deactivate own account
+        """
+        user = db.query(User).filter(User.id == user_id).first()
+        if not user:
+            raise HTTPException(status_code=404, detail="User not found")
+
+        if user.id == current_admin_id:
+            raise HTTPException(status_code=400, detail="Cannot deactivate your own account")
+
+        user.is_active = not user.is_active
+        user.updated_at = datetime.utcnow()
+        db.commit()
+        db.refresh(user)
+
+        status = "activated" if user.is_active else "deactivated"
+        logger.info(f"User {user.username} has been {status} by admin {current_admin_id}")
+        return user, f"User {user.username} has been {status}"
+
+    def get_all_shops(self, db: Session, skip: int = 0, limit: int = 100) -> Tuple[List[Shop], int]:
+        """
+        Get paginated list of all shops with total count
+
+        Args:
+            db: Database session
+            skip: Number of records to skip
+            limit: Maximum number of records to return
+
+        Returns:
+            Tuple of (shops_list, total_count)
+        """
+        total = db.query(Shop).count()
+        shops = db.query(Shop).offset(skip).limit(limit).all()
+        return shops, total
+
+    def verify_shop(self, db: Session, shop_id: int) -> Tuple[Shop, str]:
+        """
+        Toggle shop verification status
+
+        Args:
+            db: Database session
+            shop_id: ID of shop to verify/unverify
+
+        Returns:
+            Tuple of (updated_shop, status_message)
+
+        Raises:
+            HTTPException: If shop not found
+        """
+        shop = db.query(Shop).filter(Shop.id == shop_id).first()
+        if not shop:
+            raise HTTPException(status_code=404, detail="Shop not found")
+
+        shop.is_verified = not shop.is_verified
+        shop.updated_at = datetime.utcnow()
+        db.commit()
+        db.refresh(shop)
+
+        status = "verified" if shop.is_verified else "unverified"
+        logger.info(f"Shop {shop.shop_code} has been {status}")
+        return shop, f"Shop {shop.shop_code} has been {status}"
+
+    def toggle_shop_status(self, db: Session, shop_id: int) -> Tuple[Shop, str]:
+        """
+        Toggle shop active status
+
+        Args:
+            db: Database session
+            shop_id: ID of shop to activate/deactivate
+
+        Returns:
+            Tuple of (updated_shop, status_message)
+
+        Raises:
+            HTTPException: If shop not found
+        """
+        shop = db.query(Shop).filter(Shop.id == shop_id).first()
+        if not shop:
+            raise HTTPException(status_code=404, detail="Shop not found")
+
+        shop.is_active = not shop.is_active
+        shop.updated_at = datetime.utcnow()
+        db.commit()
+        db.refresh(shop)
+
+        status = "activated" if shop.is_active else "deactivated"
+        logger.info(f"Shop {shop.shop_code} has been {status}")
+        return shop, f"Shop {shop.shop_code} has been {status}"
+
+    def get_marketplace_import_jobs(
+            self,
+            db: Session,
+            marketplace: Optional[str] = None,
+            shop_name: Optional[str] = None,
+            status: Optional[str] = None,
+            skip: int = 0,
+            limit: int = 100
+    ) -> List[MarketplaceImportJobResponse]:
+        """
+        Get filtered and paginated marketplace import jobs
+
+        Args:
+            db: Database session
+            marketplace: Filter by marketplace name (case-insensitive partial match)
+            shop_name: Filter by shop name (case-insensitive partial match)
+            status: Filter by exact status
+            skip: Number of records to skip
+            limit: Maximum number of records to return
+
+        Returns:
+            List of MarketplaceImportJobResponse objects
+        """
+        query = db.query(MarketplaceImportJob)
+
+        # Apply filters
+        if marketplace:
+            query = query.filter(MarketplaceImportJob.marketplace.ilike(f"%{marketplace}%"))
+        if shop_name:
+            query = query.filter(MarketplaceImportJob.shop_name.ilike(f"%{shop_name}%"))
+        if status:
+            query = query.filter(MarketplaceImportJob.status == status)
+
+        # Order by creation date and apply pagination
+        jobs = query.order_by(MarketplaceImportJob.created_at.desc()).offset(skip).limit(limit).all()
+
+        return [
+            MarketplaceImportJobResponse(
+                job_id=job.id,
+                status=job.status,
+                marketplace=job.marketplace,
+                shop_name=job.shop_name,
+                imported=job.imported_count or 0,
+                updated=job.updated_count or 0,
+                total_processed=job.total_processed or 0,
+                error_count=job.error_count or 0,
+                error_message=job.error_message,
+                created_at=job.created_at,
+                started_at=job.started_at,
+                completed_at=job.completed_at
+            ) for job in jobs
+        ]
+
+    def get_user_by_id(self, db: Session, user_id: int) -> Optional[User]:
+        """Get user by ID"""
+        return db.query(User).filter(User.id == user_id).first()
+
+    def get_shop_by_id(self, db: Session, shop_id: int) -> Optional[Shop]:
+        """Get shop by ID"""
+        return db.query(Shop).filter(Shop.id == shop_id).first()
+
+    def user_exists(self, db: Session, user_id: int) -> bool:
+        """Check if user exists by ID"""
+        return db.query(User).filter(User.id == user_id).first() is not None
+
+    def shop_exists(self, db: Session, shop_id: int) -> bool:
+        """Check if shop exists by ID"""
+        return db.query(Shop).filter(Shop.id == shop_id).first() is not None
+
+
+# Create service instance following the same pattern as product_service
+admin_service = AdminService()
diff --git a/comprehensive_readme.md b/comprehensive_readme.md
index 885cc78d..240c253a 100644
--- a/comprehensive_readme.md
+++ b/comprehensive_readme.md
@@ -319,7 +319,7 @@ pytest tests/ -m "not slow" -v              # Fast tests only
 
 # Run specific test files
 pytest tests/test_auth.py -v                # Authentication tests
-pytest tests/test_products.py -v            # Product tests
+pytest tests/test_product.py -v            # Product tests
 pytest tests/test_stock.py -v               # Stock management tests
 ```
 
diff --git a/models/api_models.py b/models/api_models.py
index 7895953b..f3e08587 100644
--- a/models/api_models.py
+++ b/models/api_models.py
@@ -2,6 +2,7 @@
 from pydantic import BaseModel, Field, field_validator, EmailStr, ConfigDict
 from typing import Optional, List
 from datetime import datetime
+import re
 
 
 # User Authentication Models
@@ -13,8 +14,8 @@ class UserRegister(BaseModel):
     @field_validator('username')
     @classmethod
     def validate_username(cls, v):
-        if not v.isalnum():
-            raise ValueError('Username must contain only alphanumeric characters')
+        if not re.match(r'^[a-zA-Z0-9_]+$', v):
+            raise ValueError('Username must contain only letters, numbers, or underscores')
         return v.lower().strip()
 
     @field_validator('password')
diff --git a/service_layer_readme.md b/service_layer_readme.md
index 2e1bef05..e2ea77bf 100644
--- a/service_layer_readme.md
+++ b/service_layer_readme.md
@@ -206,7 +206,7 @@ product_service = ProductService()
 ### Step 2: Refactor Router
 
 ```python
-# products.py
+# product.py
 from product_service import product_service
 
 @router.post("/products", response_model=ProductResponse)
diff --git a/tests/conftest.py b/tests/conftest.py
index f01efb16..f1bee3b7 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -12,6 +12,7 @@ from app.core.database import get_db, Base
 # Import all models to ensure they're registered with Base metadata
 from models.database_models import User, Product, Stock, Shop, MarketplaceImportJob, ShopProduct
 from middleware.auth import AuthManager
+import uuid
 
 # Use in-memory SQLite database for tests
 SQLALCHEMY_TEST_DATABASE_URL = "sqlite:///:memory:"
@@ -81,11 +82,12 @@ def auth_manager():
 
 @pytest.fixture
 def test_user(db, auth_manager):
-    """Create a test user"""
+    """Create a test user with unique username"""
+    unique_id = str(uuid.uuid4())[:8]  # Short unique identifier
     hashed_password = auth_manager.hash_password("testpass123")
     user = User(
-        email="test@example.com",
-        username="testuser",
+        email=f"test_{unique_id}@example.com",
+        username=f"testuser_{unique_id}",
         hashed_password=hashed_password,
         role="user",
         is_active=True
@@ -98,11 +100,12 @@ def test_user(db, auth_manager):
 
 @pytest.fixture
 def test_admin(db, auth_manager):
-    """Create a test admin user"""
+    """Create a test admin user with unique username"""
+    unique_id = str(uuid.uuid4())[:8]  # Short unique identifier
     hashed_password = auth_manager.hash_password("adminpass123")
     admin = User(
-        email="admin@example.com",
-        username="admin",
+        email=f"admin_{unique_id}@example.com",
+        username=f"admin_{unique_id}",
         hashed_password=hashed_password,
         role="admin",
         is_active=True
@@ -117,7 +120,7 @@ def test_admin(db, auth_manager):
 def auth_headers(client, test_user):
     """Get authentication headers for test user"""
     response = client.post("/api/v1/auth/login", json={
-        "username": "testuser",
+        "username": test_user.username,
         "password": "testpass123"
     })
     assert response.status_code == 200, f"Login failed: {response.text}"
@@ -129,7 +132,7 @@ def auth_headers(client, test_user):
 def admin_headers(client, test_admin):
     """Get authentication headers for admin user"""
     response = client.post("/api/v1/auth/login", json={
-        "username": "admin",
+        "username": test_admin.username,
         "password": "adminpass123"
     })
     assert response.status_code == 200, f"Admin login failed: {response.text}"
@@ -160,10 +163,11 @@ def test_product(db):
 
 @pytest.fixture
 def test_shop(db, test_user):
-    """Create a test shop"""
+    """Create a test shop with unique shop code"""
+    unique_id = str(uuid.uuid4())[:8]  # Short unique identifier
     shop = Shop(
-        shop_code="TESTSHOP",
-        shop_name="Test Shop",
+        shop_code=f"TESTSHOP_{unique_id}",
+        shop_name=f"Test Shop {unique_id}",
         owner_id=test_user.id,
         is_active=True,
         is_verified=True
@@ -190,6 +194,50 @@ def test_stock(db, test_product, test_shop):
     return stock
 
 
+@pytest.fixture
+def test_marketplace_job(db, test_shop):  # Add test_shop dependency
+    """Create a test marketplace import job"""
+    job = MarketplaceImportJob(
+        marketplace="amazon",
+        shop_name="Test Import Shop",
+        status="completed",
+        source_url="https://test-marketplace.example.com/import",
+        shop_id=test_shop.id,  # Add required shop_id
+        imported_count=5,
+        updated_count=3,
+        total_processed=8,
+        error_count=0,
+        error_message=None
+    )
+    db.add(job)
+    db.commit()
+    db.refresh(job)
+    return job
+
+
+def create_test_import_job(db, shop_id, **kwargs):  # Add shop_id parameter
+    """Helper function to create MarketplaceImportJob with defaults"""
+    defaults = {
+        'marketplace': 'test',
+        'shop_name': 'Test Shop',
+        'status': 'pending',
+        'source_url': 'https://test.example.com/import',
+        'shop_id': shop_id,  # Add required shop_id
+        'imported_count': 0,
+        'updated_count': 0,
+        'total_processed': 0,
+        'error_count': 0,
+        'error_message': None
+    }
+    defaults.update(kwargs)
+
+    job = MarketplaceImportJob(**defaults)
+    db.add(job)
+    db.commit()
+    db.refresh(job)
+    return job
+
+
 # Cleanup fixture to ensure clean state
 @pytest.fixture(autouse=True)
 def cleanup():
diff --git a/tests/test_admin.py b/tests/test_admin.py
index fb3d14a2..6fe288f9 100644
--- a/tests/test_admin.py
+++ b/tests/test_admin.py
@@ -11,6 +11,10 @@ class TestAdminAPI:
         data = response.json()
         assert len(data) >= 2  # test_user + admin user
 
+        # Check that test_user is in the response
+        user_ids = [user["id"] for user in data if "id" in user]
+        assert test_user.id in user_ids
+
     def test_get_all_users_non_admin(self, client, auth_headers):
         """Test non-admin trying to access admin endpoint"""
         response = client.get("/api/v1/admin/users", headers=auth_headers)
@@ -23,7 +27,24 @@ class TestAdminAPI:
         response = client.put(f"/api/v1/admin/users/{test_user.id}/status", headers=admin_headers)
 
         assert response.status_code == 200
-        assert "deactivated" in response.json()["message"] or "activated" in response.json()["message"]
+        message = response.json()["message"]
+        assert "deactivated" in message or "activated" in message
+        # Verify the username is in the message
+        assert test_user.username in message
+
+    def test_toggle_user_status_user_not_found(self, client, admin_headers):
+        """Test admin toggling status for non-existent user"""
+        response = client.put("/api/v1/admin/users/99999/status", headers=admin_headers)
+
+        assert response.status_code == 404
+        assert "User not found" in response.json()["detail"]
+
+    def test_toggle_user_status_cannot_deactivate_self(self, client, admin_headers, test_admin):
+        """Test that admin cannot deactivate their own account"""
+        response = client.put(f"/api/v1/admin/users/{test_admin.id}/status", headers=admin_headers)
+
+        assert response.status_code == 400
+        assert "Cannot deactivate your own account" in response.json()["detail"]
 
     def test_get_all_shops_admin(self, client, admin_headers, test_shop):
         """Test admin getting all shops"""
@@ -32,3 +53,115 @@ class TestAdminAPI:
         assert response.status_code == 200
         data = response.json()
         assert data["total"] >= 1
+        assert len(data["shops"]) >= 1
+
+        # Check that test_shop is in the response
+        shop_codes = [shop["shop_code"] for shop in data["shops"] if "shop_code" in shop]
+        assert test_shop.shop_code in shop_codes
+
+    def test_get_all_shops_non_admin(self, client, auth_headers):
+        """Test non-admin trying to access admin shop endpoint"""
+        response = client.get("/api/v1/admin/shops", headers=auth_headers)
+
+        assert response.status_code == 403
+        assert "Access denied" in response.json()["detail"] or "admin" in response.json()["detail"].lower()
+
+    def test_verify_shop_admin(self, client, admin_headers, test_shop):
+        """Test admin verifying/unverifying shop"""
+        response = client.put(f"/api/v1/admin/shops/{test_shop.id}/verify", headers=admin_headers)
+
+        assert response.status_code == 200
+        message = response.json()["message"]
+        assert "verified" in message or "unverified" in message
+        assert test_shop.shop_code in message
+
+    def test_verify_shop_not_found(self, client, admin_headers):
+        """Test admin verifying non-existent shop"""
+        response = client.put("/api/v1/admin/shops/99999/verify", headers=admin_headers)
+
+        assert response.status_code == 404
+        assert "Shop not found" in response.json()["detail"]
+
+    def test_toggle_shop_status_admin(self, client, admin_headers, test_shop):
+        """Test admin toggling shop status"""
+        response = client.put(f"/api/v1/admin/shops/{test_shop.id}/status", headers=admin_headers)
+
+        assert response.status_code == 200
+        message = response.json()["message"]
+        assert "activated" in message or "deactivated" in message
+        assert test_shop.shop_code in message
+
+    def test_toggle_shop_status_not_found(self, client, admin_headers):
+        """Test admin toggling status for non-existent shop"""
+        response = client.put("/api/v1/admin/shops/99999/status", headers=admin_headers)
+
+        assert response.status_code == 404
+        assert "Shop not found" in response.json()["detail"]
+
+    def test_get_marketplace_import_jobs_admin(self, client, admin_headers, test_marketplace_job):
+        """Test admin getting marketplace import jobs"""
+        response = client.get("/api/v1/admin/marketplace-import-jobs", headers=admin_headers)
+
+        assert response.status_code == 200
+        data = response.json()
+        assert len(data) >= 1
+
+        # Check that test_marketplace_job is in the response
+        job_ids = [job["job_id"] for job in data if "job_id" in job]
+        assert test_marketplace_job.id in job_ids
+
+    def test_get_marketplace_import_jobs_with_filters(self, client, admin_headers, test_marketplace_job):
+        """Test admin getting marketplace import jobs with filters"""
+        response = client.get(
+            "/api/v1/admin/marketplace-import-jobs",
+            params={"marketplace": test_marketplace_job.marketplace},
+            headers=admin_headers
+        )
+
+        assert response.status_code == 200
+        data = response.json()
+        assert len(data) >= 1
+        assert all(job["marketplace"] == test_marketplace_job.marketplace for job in data)
+
+    def test_get_marketplace_import_jobs_non_admin(self, client, auth_headers):
+        """Test non-admin trying to access marketplace import jobs"""
+        response = client.get("/api/v1/admin/marketplace-import-jobs", headers=auth_headers)
+
+        assert response.status_code == 403
+        assert "Access denied" in response.json()["detail"] or "admin" in response.json()["detail"].lower()
+
+    def test_admin_endpoints_require_authentication(self, client):
+        """Test that admin endpoints require authentication"""
+        endpoints = [
+            "/api/v1/admin/users",
+            "/api/v1/admin/shops",
+            "/api/v1/admin/marketplace-import-jobs"
+        ]
+
+        for endpoint in endpoints:
+            response = client.get(endpoint)
+            assert response.status_code == 401  # Unauthorized
+
+    def test_admin_pagination_users(self, client, admin_headers, test_user, test_admin):
+        """Test user pagination works correctly"""
+        # Test first page
+        response = client.get("/api/v1/admin/users?skip=0&limit=1", headers=admin_headers)
+        assert response.status_code == 200
+        data = response.json()
+        assert len(data) == 1
+
+        # Test second page
+        response = client.get("/api/v1/admin/users?skip=1&limit=1", headers=admin_headers)
+        assert response.status_code == 200
+        data = response.json()
+        assert len(data) >= 0  # Could be 1 or 0 depending on total users
+
+    def test_admin_pagination_shops(self, client, admin_headers, test_shop):
+        """Test shop pagination works correctly"""
+        response = client.get("/api/v1/admin/shops?skip=0&limit=1", headers=admin_headers)
+        assert response.status_code == 200
+        data = response.json()
+        assert data["total"] >= 1
+        assert len(data["shops"]) >= 0
+        assert "skip" in data
+        assert "limit" in data
diff --git a/tests/test_admin_service.py b/tests/test_admin_service.py
new file mode 100644
index 00000000..4c92c8dc
--- /dev/null
+++ b/tests/test_admin_service.py
@@ -0,0 +1,359 @@
+# tests/test_admin_service.py
+import pytest
+from datetime import datetime
+from fastapi import HTTPException
+
+from app.services.admin_service import AdminService
+from models.database_models import User, Shop, MarketplaceImportJob
+
+
+class TestAdminService:
+    """Test suite for AdminService following the application's testing patterns"""
+
+    def setup_method(self):
+        """Setup method following the same pattern as product service tests"""
+        self.service = AdminService()
+
+    def test_get_all_users(self, db, test_user, test_admin):
+        """Test getting all users with pagination"""
+        users = self.service.get_all_users(db, skip=0, limit=10)
+
+        assert len(users) >= 2  # test_user + test_admin
+        user_ids = [user.id for user in users]
+        assert test_user.id in user_ids
+        assert test_admin.id in user_ids
+
+    def test_get_all_users_with_pagination(self, db, test_user, test_admin):
+        """Test user pagination works correctly"""
+        users = self.service.get_all_users(db, skip=0, limit=1)
+
+        assert len(users) == 1
+
+        users_second_page = self.service.get_all_users(db, skip=1, limit=1)
+        assert len(users_second_page) == 1
+        assert users[0].id != users_second_page[0].id
+
+    def test_toggle_user_status_deactivate(self, db, test_user, test_admin):
+        """Test deactivating a user"""
+        assert test_user.is_active is True
+
+        user, message = self.service.toggle_user_status(db, test_user.id, test_admin.id)
+
+        assert user.id == test_user.id
+        assert user.is_active is False
+        assert f"{user.username} has been deactivated" in message
+
+    def test_toggle_user_status_activate(self, db, test_user, test_admin):
+        """Test activating a user"""
+        # First deactivate the user
+        test_user.is_active = False
+        db.commit()
+
+        user, message = self.service.toggle_user_status(db, test_user.id, test_admin.id)
+
+        assert user.id == test_user.id
+        assert user.is_active is True
+        assert f"{user.username} has been activated" in message
+
+    def test_toggle_user_status_user_not_found(self, db, test_admin):
+        """Test toggle user status when user not found"""
+        with pytest.raises(HTTPException) as exc_info:
+            self.service.toggle_user_status(db, 99999, test_admin.id)
+
+        assert exc_info.value.status_code == 404
+        assert "User not found" in str(exc_info.value.detail)
+
+    def test_toggle_user_status_cannot_deactivate_self(self, db, test_admin):
+        """Test that admin cannot deactivate their own account"""
+        with pytest.raises(HTTPException) as exc_info:
+            self.service.toggle_user_status(db, test_admin.id, test_admin.id)
+
+        assert exc_info.value.status_code == 400
+        assert "Cannot deactivate your own account" in str(exc_info.value.detail)
+
+    def test_get_all_shops(self, db, test_shop):
+        """Test getting all shops with total count"""
+        shops, total = self.service.get_all_shops(db, skip=0, limit=10)
+
+        assert total >= 1
+        assert len(shops) >= 1
+        shop_codes = [shop.shop_code for shop in shops]
+        assert test_shop.shop_code in shop_codes
+
+    def test_get_all_shops_with_pagination(self, db, test_shop):
+        """Test shop pagination works correctly"""
+        # Create additional shop for pagination test using the helper function
+        from conftest import create_test_import_job  # If you added the helper function
+
+        # Or create directly with proper fields
+        additional_shop = Shop(
+            shop_code=f"{test_shop.shop_code}_2",
+            shop_name="Test Shop 2",
+            owner_id=test_shop.owner_id,
+            is_active=True,
+            is_verified=False
+        )
+        db.add(additional_shop)
+        db.commit()
+
+        shops_page_1 = self.service.get_all_shops(db, skip=0, limit=1)
+        assert len(shops_page_1[0]) == 1
+
+        shops_page_2 = self.service.get_all_shops(db, skip=1, limit=1)
+        assert len(shops_page_2[0]) == 1
+
+        # Ensure different shops on different pages
+        assert shops_page_1[0][0].id != shops_page_2[0][0].id
+
+    def test_verify_shop_mark_verified(self, db, test_shop):
+        """Test marking shop as verified"""
+        # Ensure shop starts unverified
+        test_shop.is_verified = False
+        db.commit()
+
+        shop, message = self.service.verify_shop(db, test_shop.id)
+
+        assert shop.id == test_shop.id
+        assert shop.is_verified is True
+        assert f"{shop.shop_code} has been verified" in message
+
+    def test_verify_shop_mark_unverified(self, db, test_shop):
+        """Test marking shop as unverified"""
+        # Ensure shop starts verified
+        test_shop.is_verified = True
+        db.commit()
+
+        shop, message = self.service.verify_shop(db, test_shop.id)
+
+        assert shop.id == test_shop.id
+        assert shop.is_verified is False
+        assert f"{shop.shop_code} has been unverified" in message
+
+    def test_verify_shop_not_found(self, db):
+        """Test verify shop when shop not found"""
+        with pytest.raises(HTTPException) as exc_info:
+            self.service.verify_shop(db, 99999)
+
+        assert exc_info.value.status_code == 404
+        assert "Shop not found" in str(exc_info.value.detail)
+
+    def test_toggle_shop_status_deactivate(self, db, test_shop):
+        """Test deactivating a shop"""
+        assert test_shop.is_active is True
+
+        shop, message = self.service.toggle_shop_status(db, test_shop.id)
+
+        assert shop.id == test_shop.id
+        assert shop.is_active is False
+        assert f"{shop.shop_code} has been deactivated" in message
+
+    def test_toggle_shop_status_activate(self, db, test_shop):
+        """Test activating a shop"""
+        # First deactivate the shop
+        test_shop.is_active = False
+        db.commit()
+
+        shop, message = self.service.toggle_shop_status(db, test_shop.id)
+
+        assert shop.id == test_shop.id
+        assert shop.is_active is True
+        assert f"{shop.shop_code} has been activated" in message
+
+    def test_toggle_shop_status_not_found(self, db):
+        """Test toggle shop status when shop not found"""
+        with pytest.raises(HTTPException) as exc_info:
+            self.service.toggle_shop_status(db, 99999)
+
+        assert exc_info.value.status_code == 404
+        assert "Shop not found" in str(exc_info.value.detail)
+
+    def test_get_marketplace_import_jobs_no_filters(self, db, test_marketplace_job):
+        """Test getting marketplace import jobs without filters using fixture"""
+        result = self.service.get_marketplace_import_jobs(db, skip=0, limit=10)
+
+        assert len(result) >= 1
+        # Find our test job in the results
+        test_job = next((job for job in result if job.job_id == test_marketplace_job.id), None)
+        assert test_job is not None
+        assert test_job.marketplace == test_marketplace_job.marketplace
+        assert test_job.shop_name == test_marketplace_job.shop_name
+        assert test_job.status == test_marketplace_job.status
+
+    def test_get_marketplace_import_jobs_with_marketplace_filter(self, db, test_marketplace_job):
+        """Test getting marketplace import jobs filtered by marketplace"""
+        # Create additional job with different marketplace
+        other_job = MarketplaceImportJob(
+            marketplace="ebay",
+            shop_name="eBay Shop",
+            status="completed",
+            source_url="https://ebay.example.com/import"
+        )
+        db.add(other_job)
+        db.commit()
+
+        # Filter by the test marketplace job's marketplace
+        result = self.service.get_marketplace_import_jobs(db, marketplace=test_marketplace_job.marketplace)
+
+        assert len(result) >= 1
+        # All results should match the marketplace filter
+        for job in result:
+            assert test_marketplace_job.marketplace.lower() in job.marketplace.lower()
+
+    def test_get_marketplace_import_jobs_with_shop_filter(self, db, test_marketplace_job):
+        """Test getting marketplace import jobs filtered by shop name"""
+        # Create additional job with different shop name
+        other_job = MarketplaceImportJob(
+            marketplace="amazon",
+            shop_name="Different Shop Name",
+            status="completed",
+            source_url="https://different.example.com/import"
+        )
+        db.add(other_job)
+        db.commit()
+
+        # Filter by the test marketplace job's shop name
+        result = self.service.get_marketplace_import_jobs(db, shop_name=test_marketplace_job.shop_name)
+
+        assert len(result) >= 1
+        # All results should match the shop name filter
+        for job in result:
+            assert test_marketplace_job.shop_name.lower() in job.shop_name.lower()
+
+    def test_get_marketplace_import_jobs_with_status_filter(self, db, test_marketplace_job):
+        """Test getting marketplace import jobs filtered by status"""
+        # Create additional job with different status
+        other_job = MarketplaceImportJob(
+            marketplace="amazon",
+            shop_name="Test Shop",
+            status="pending",
+            source_url="https://pending.example.com/import"
+        )
+        db.add(other_job)
+        db.commit()
+
+        # Filter by the test marketplace job's status
+        result = self.service.get_marketplace_import_jobs(db, status=test_marketplace_job.status)
+
+        assert len(result) >= 1
+        # All results should match the status filter
+        for job in result:
+            assert job.status == test_marketplace_job.status
+
+    def test_get_marketplace_import_jobs_with_multiple_filters(self, db, test_marketplace_job, test_shop):
+        """Test getting marketplace import jobs with multiple filters"""
+        # Create jobs that don't match all filters
+        non_matching_job1 = MarketplaceImportJob(
+            marketplace="ebay",  # Different marketplace
+            shop_name=test_marketplace_job.shop_name,
+            status=test_marketplace_job.status,
+            source_url="https://non-matching1.example.com/import",
+            shop_id=test_shop.id  # Add required shop_id
+        )
+        non_matching_job2 = MarketplaceImportJob(
+            marketplace=test_marketplace_job.marketplace,
+            shop_name="Different Shop",  # Different shop name
+            status=test_marketplace_job.status,
+            source_url="https://non-matching2.example.com/import",
+            shop_id=test_shop.id  # Add required shop_id
+        )
+        db.add_all([non_matching_job1, non_matching_job2])
+        db.commit()
+
+        # Apply all three filters matching the test job
+        result = self.service.get_marketplace_import_jobs(
+            db,
+            marketplace=test_marketplace_job.marketplace,
+            shop_name=test_marketplace_job.shop_name,
+            status=test_marketplace_job.status
+        )
+
+        assert len(result) >= 1
+        # Find our test job in the results
+        test_job = next((job for job in result if job.job_id == test_marketplace_job.id), None)
+        assert test_job is not None
+        assert test_job.marketplace == test_marketplace_job.marketplace
+        assert test_job.shop_name == test_marketplace_job.shop_name
+        assert test_job.status == test_marketplace_job.status
+
+    def test_get_marketplace_import_jobs_null_values(self, db):
+        """Test that marketplace import jobs handle null values correctly"""
+        # Create job with null values but required fields
+        job = MarketplaceImportJob(
+            marketplace="test",
+            shop_name="Test Shop",
+            status="pending",
+            source_url="https://test.example.com/import",
+            imported_count=None,
+            updated_count=None,
+            total_processed=None,
+            error_count=None,
+            error_message=None
+        )
+        db.add(job)
+        db.commit()
+
+        result = self.service.get_marketplace_import_jobs(db)
+
+        assert len(result) >= 1
+        # Find the job with null values
+        null_job = next((j for j in result if j.job_id == job.id), None)
+        assert null_job is not None
+        assert null_job.imported == 0  # None converted to 0
+        assert null_job.updated == 0
+        assert null_job.total_processed == 0
+        assert null_job.error_count == 0
+        assert null_job.error_message is None
+
+    def test_get_user_by_id(self, db, test_user):
+        """Test getting user by ID using fixture"""
+        user = self.service.get_user_by_id(db, test_user.id)
+
+        assert user is not None
+        assert user.id == test_user.id
+        assert user.email == test_user.email
+        assert user.username == test_user.username
+
+    def test_get_user_by_id_not_found(self, db):
+        """Test getting user by ID when user doesn't exist"""
+        user = self.service.get_user_by_id(db, 99999)
+
+        assert user is None
+
+    def test_get_shop_by_id(self, db, test_shop):
+        """Test getting shop by ID using fixture"""
+        shop = self.service.get_shop_by_id(db, test_shop.id)
+
+        assert shop is not None
+        assert shop.id == test_shop.id
+        assert shop.shop_code == test_shop.shop_code
+        assert shop.shop_name == test_shop.shop_name
+
+    def test_get_shop_by_id_not_found(self, db):
+        """Test getting shop by ID when shop doesn't exist"""
+        shop = self.service.get_shop_by_id(db, 99999)
+
+        assert shop is None
+
+    def test_user_exists_true(self, db, test_user):
+        """Test user_exists returns True when user exists"""
+        exists = self.service.user_exists(db, test_user.id)
+
+        assert exists is True
+
+    def test_user_exists_false(self, db):
+        """Test user_exists returns False when user doesn't exist"""
+        exists = self.service.user_exists(db, 99999)
+
+        assert exists is False
+
+    def test_shop_exists_true(self, db, test_shop):
+        """Test shop_exists returns True when shop exists"""
+        exists = self.service.shop_exists(db, test_shop.id)
+
+        assert exists is True
+
+    def test_shop_exists_false(self, db):
+        """Test shop_exists returns False when shop doesn't exist"""
+        exists = self.service.shop_exists(db, 99999)
+
+        assert exists is False
diff --git a/tests/test_auth.py b/tests/test_auth.py
index 75186165..b42c93ee 100644
--- a/tests/test_auth.py
+++ b/tests/test_auth.py
@@ -23,7 +23,7 @@ class TestAuthenticationAPI:
     def test_register_user_duplicate_email(self, client, test_user):
         """Test registration with duplicate email"""
         response = client.post("/api/v1/auth/register", json={
-            "email": "test@example.com",  # Same as test_user
+            "email": test_user.email,  # Same as test_user
             "username": "newuser",
             "password": "securepass123"
         })
@@ -35,7 +35,7 @@ class TestAuthenticationAPI:
         """Test registration with duplicate username"""
         response = client.post("/api/v1/auth/register", json={
             "email": "new@example.com",
-            "username": "testuser",  # Same as test_user
+            "username": test_user.username,  # Same as test_user
             "password": "securepass123"
         })
 
@@ -45,7 +45,7 @@ class TestAuthenticationAPI:
     def test_login_success(self, client, test_user):
         """Test successful login"""
         response = client.post("/api/v1/auth/login", json={
-            "username": "testuser",
+            "username": test_user.username,
             "password": "testpass123"
         })
 
@@ -54,7 +54,7 @@ class TestAuthenticationAPI:
         assert "access_token" in data
         assert data["token_type"] == "bearer"
         assert "expires_in" in data
-        assert data["user"]["username"] == "testuser"
+        assert data["user"]["username"] == test_user.username
 
     def test_login_wrong_password(self, client, test_user):
         """Test login with wrong password"""
@@ -75,14 +75,14 @@ class TestAuthenticationAPI:
 
         assert response.status_code == 401
 
-    def test_get_current_user_info(self, client, auth_headers):
+    def test_get_current_user_info(self, client, auth_headers, test_user):
         """Test getting current user info"""
         response = client.get("/api/v1/auth/me", headers=auth_headers)
 
         assert response.status_code == 200
         data = response.json()
-        assert data["username"] == "testuser"
-        assert data["email"] == "test@example.com"
+        assert data["username"] == test_user.username
+        assert data["email"] == test_user.email
 
     def test_get_current_user_no_auth(self, client):
         """Test getting current user without authentication"""
diff --git a/tests/test_performance.py b/tests/test_performance.py
index 6b31544a..23eba39a 100644
--- a/tests/test_performance.py
+++ b/tests/test_performance.py
@@ -2,6 +2,8 @@
 import pytest
 import time
 
+from models.database_models import Product
+
 
 class TestPerformance:
     def test_product_list_performance(self, client, auth_headers, db):
@@ -22,7 +24,7 @@ class TestPerformance:
 
         # Time the request
         start_time = time.time()
-        response = client.get("/api/v1/products?limit=100", headers=auth_headers)
+        response = client.get("/api/v1/product?limit=100", headers=auth_headers)
         end_time = time.time()
 
         assert response.status_code == 200
@@ -48,7 +50,7 @@ class TestPerformance:
 
         # Time search request
         start_time = time.time()
-        response = client.get("/api/v1/products?search=Searchable", headers=auth_headers)
+        response = client.get("/api/v1/product?search=Searchable", headers=auth_headers)
         end_time = time.time()
 
         assert response.status_code == 200
diff --git a/tests/test_products.py b/tests/test_product.py
similarity index 97%
rename from tests/test_products.py
rename to tests/test_product.py
index dc9082a1..c425a2dc 100644
--- a/tests/test_products.py
+++ b/tests/test_product.py
@@ -1,11 +1,11 @@
-# tests/test_products.py
+# tests/test_product.py
 import pytest
 
 
 class TestProductsAPI:
     def test_get_products_empty(self, client, auth_headers):
         """Test getting products when none exist"""
-        response = client.get("/api/v1/products", headers=auth_headers)
+        response = client.get("/api/v1/product", headers=auth_headers)
 
         assert response.status_code == 200
         data = response.json()
diff --git a/tests/test_shops.py b/tests/test_shop.py
similarity index 98%
rename from tests/test_shops.py
rename to tests/test_shop.py
index 225285fb..9f721e18 100644
--- a/tests/test_shops.py
+++ b/tests/test_shop.py
@@ -1,4 +1,4 @@
-# tests/test_shops.py
+# tests/test_shop.py
 import pytest