diff --git a/.gitignore b/.gitignore
new file mode 100644
index 00000000..a991a6b7
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,103 @@
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# PyInstaller
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.nox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+*.py,cover
+.hypothesis/
+.pytest_cache/
+
+# MkDocs documentation
+site/
+
+# PyCharm
+.idea/
+
+# VS Code
+.vscode/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# pyenv
+.python-version
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# Pyre type checker
+.pyre/
+
+# pytype
+.pytype/
+
+# Cython debug symbols
+cython_debug/
+
+# Environment variables
+.env
+.env.*
+
+# Virtual environments
+venv/
+ENV/
+env/
+.venv/
+
+# macOS
+.DS_Store
+
+# Windows
+Thumbs.db
+ehthumbs.db
+Desktop.ini
+
+# Database files
+*.sqlite
+*.sqlite3
+*.db
+*.sql
+
+# Log files
+*.log
+logs/
diff --git a/docs/testing/index.md b/docs/testing/index.md
new file mode 100644
index 00000000..dd0189ad
--- /dev/null
+++ b/docs/testing/index.md
@@ -0,0 +1,299 @@
+# Testing Overview
+
+Our comprehensive test suite ensures code quality, reliability, and maintainability. This section covers everything you need to know about testing in the Letzshop Import project.
+
+## Test Structure
+
+We use a hierarchical test organization based on test types and scope:
+
+```
+tests/
+├── conftest.py                    # Core test configuration and fixtures
+├── pytest.ini                    # Pytest configuration with custom markers
+├── fixtures/                     # Shared test fixtures by domain
+├── unit/                         # Fast, isolated component tests
+├── integration/                  # Multi-component interaction tests
+├── performance/                  # Performance and load tests
+├── system/                      # End-to-end system behavior tests
+└── test_data/                   # Test data files (CSV, JSON, etc.)
+```
+
+## Test Types
+
+### 🔧 Unit Tests
+**Purpose**: Test individual components in isolation  
+**Speed**: Very fast (< 1 second each)  
+**Scope**: Single function, method, or class  
+
+```bash
+# Run unit tests
+pytest -m unit
+```
+
+**Examples**:
+- Data processing utilities
+- Model validation
+- Service business logic
+- Individual API endpoint handlers
+
+### 🔗 Integration Tests  
+**Purpose**: Test component interactions  
+**Speed**: Fast to moderate (1-5 seconds each)  
+**Scope**: Multiple components working together  
+
+```bash
+# Run integration tests
+pytest -m integration
+```
+
+**Examples**:
+- API endpoints with database
+- Service layer interactions
+- Authentication workflows
+- File processing pipelines
+
+### 🏗️ System Tests
+**Purpose**: Test complete application behavior  
+**Speed**: Moderate (5-30 seconds each)  
+**Scope**: End-to-end user scenarios  
+
+```bash
+# Run system tests
+pytest -m system
+```
+
+**Examples**:
+- Complete user registration flow
+- Full CSV import process
+- Multi-step workflows
+- Error handling across layers
+
+### ⚡ Performance Tests
+**Purpose**: Validate performance requirements  
+**Speed**: Slow (30+ seconds each)  
+**Scope**: Load, stress, and performance testing  
+
+```bash
+# Run performance tests
+pytest -m performance
+```
+
+**Examples**:
+- API response times
+- Database query performance
+- Large file processing
+- Concurrent user scenarios
+
+## Running Tests
+
+### Basic Commands
+
+```bash
+# Run all tests
+pytest
+
+# Run with verbose output
+pytest -v
+
+# Run specific test type
+pytest -m unit
+pytest -m integration
+pytest -m "unit or integration"
+
+# Run tests in specific directory
+pytest tests/unit/
+pytest tests/integration/api/
+
+# Run specific test file
+pytest tests/unit/services/test_product_service.py
+
+# Run specific test class
+pytest tests/unit/services/test_product_service.py::TestProductService
+
+# Run specific test method
+pytest tests/unit/services/test_product_service.py::TestProductService::test_create_product_success
+```
+
+### Advanced Options
+
+```bash
+# Run with coverage report
+pytest --cov=app --cov-report=html
+
+# Run tests matching pattern
+pytest -k "product and not slow"
+
+# Stop on first failure
+pytest -x
+
+# Run failed tests from last run
+pytest --lf
+
+# Run tests in parallel (if pytest-xdist installed)
+pytest -n auto
+
+# Show slowest tests
+pytest --durations=10
+```
+
+## Test Markers
+
+We use pytest markers to categorize and selectively run tests:
+
+| Marker | Purpose |
+|--------|---------|
+| `@pytest.mark.unit` | Fast, isolated component tests |
+| `@pytest.mark.integration` | Multi-component interaction tests |
+| `@pytest.mark.system` | End-to-end system tests |
+| `@pytest.mark.performance` | Performance and load tests |
+| `@pytest.mark.slow` | Long-running tests |
+| `@pytest.mark.api` | API endpoint tests |
+| `@pytest.mark.database` | Tests requiring database |
+| `@pytest.mark.auth` | Authentication/authorization tests |
+
+### Example Usage
+
+```python
+@pytest.mark.unit
+@pytest.mark.products
+class TestProductService:
+    def test_create_product_success(self):
+        # Test implementation
+        pass
+
+@pytest.mark.integration
+@pytest.mark.api
+@pytest.mark.database
+def test_product_creation_endpoint():
+    # Test implementation
+    pass
+```
+
+## Test Configuration
+
+### pytest.ini
+Our pytest configuration includes:
+
+- **Custom markers** for test categorization
+- **Coverage settings** with 80% minimum threshold
+- **Test discovery** patterns and paths
+- **Output formatting** for better readability
+
+### conftest.py
+Core test fixtures and configuration:
+
+- **Database fixtures** for test isolation
+- **Authentication fixtures** for user/admin testing
+- **Client fixtures** for API testing
+- **Mock fixtures** for external dependencies
+
+## Test Data Management
+
+### Fixtures
+We organize fixtures by domain:
+
+```python
+# tests/fixtures/product_fixtures.py
+@pytest.fixture
+def sample_product():
+    return {
+        "name": "Test Product",
+        "gtin": "1234567890123",
+        "price": "19.99"
+    }
+
+@pytest.fixture  
+def product_factory():
+    def _create_product(**kwargs):
+        defaults = {"name": "Test", "gtin": "1234567890123"}
+        defaults.update(kwargs)
+        return defaults
+    return _create_product
+```
+
+### Test Data Files
+Static test data in `tests/test_data/`:
+
+- CSV files for import testing
+- JSON files for API testing
+- Sample configuration files
+
+## Coverage Requirements
+
+We maintain high test coverage standards:
+
+- **Minimum coverage**: 80% overall
+- **Critical paths**: 95%+ coverage required
+- **New code**: Must include tests
+- **HTML reports**: Generated in `htmlcov/`
+
+```bash
+# Generate coverage report
+pytest --cov=app --cov-report=html --cov-report=term-missing
+```
+
+## Best Practices
+
+### Test Naming
+- Use descriptive test names that explain the scenario
+- Follow the pattern: `test_{action}_{scenario}_{expected_outcome}`
+- See our [Test Naming Conventions](test-naming-conventions.md) for details
+
+### Test Structure  
+- **Arrange**: Set up test data and conditions
+- **Act**: Execute the code being tested  
+- **Assert**: Verify the expected outcome
+
+```python
+def test_create_product_with_valid_data_returns_product(self):
+    # Arrange
+    product_data = {"name": "Test", "gtin": "1234567890123"}
+    
+    # Act
+    result = product_service.create_product(product_data)
+    
+    # Assert
+    assert result is not None
+    assert result.name == "Test"
+```
+
+### Test Isolation
+- Each test should be independent
+- Use database transactions that rollback
+- Mock external dependencies
+- Clean up test data
+
+## Continuous Integration
+
+Our CI pipeline runs:
+
+1. **Linting** with flake8 and black
+2. **Type checking** with mypy  
+3. **Security scanning** with bandit
+4. **Unit tests** on every commit
+5. **Integration tests** on pull requests
+6. **Performance tests** on releases
+
+## Tools and Libraries
+
+- **pytest**: Test framework and runner
+- **pytest-cov**: Coverage reporting
+- **pytest-asyncio**: Async test support
+- **pytest-mock**: Mocking utilities  
+- **faker**: Test data generation
+- **httpx**: HTTP client for API testing
+- **factory-boy**: Test object factories
+
+## Getting Started
+
+1. **Read the conventions**: [Test Naming Conventions](test-naming-conventions.md)
+2. **Run existing tests**: `pytest -v`
+3. **Write your first test**: See examples in existing test files
+4. **Check coverage**: `pytest --cov`
+
+## Need Help?
+
+- **Examples**: Look at existing tests in `tests/` directory
+- **Documentation**: This testing section has detailed guides
+- **Issues**: Create a GitHub issue for testing questions
+- **Standards**: Follow our [naming conventions](test-naming-conventions.md)
\ No newline at end of file
diff --git a/docs/testing/running_tests.md b/docs/testing/running_tests.md
new file mode 100644
index 00000000..533a4270
--- /dev/null
+++ b/docs/testing/running_tests.md
@@ -0,0 +1,403 @@
+# Running Tests
+
+This guide covers everything you need to know about running tests in the Letzshop Import project.
+
+## Prerequisites
+
+Ensure you have the test dependencies installed:
+
+```bash
+pip install -r tests/requirements-test.txt
+```
+
+Required packages:
+- `pytest>=7.4.0` - Test framework
+- `pytest-cov>=4.1.0` - Coverage reporting  
+- `pytest-asyncio>=0.21.0` - Async test support
+- `pytest-mock>=3.11.0` - Mocking utilities
+- `httpx>=0.24.0` - HTTP client for API tests
+- `faker>=19.0.0` - Test data generation
+
+## Basic Test Commands
+
+### Run All Tests
+```bash
+# Run the entire test suite
+pytest
+
+# Run with verbose output
+pytest -v
+
+# Run with very verbose output (show individual test results)
+pytest -vv
+```
+
+### Run by Test Type
+```bash
+# Run only unit tests (fast)
+pytest -m unit
+
+# Run only integration tests  
+pytest -m integration
+
+# Run unit and integration tests
+pytest -m "unit or integration"
+
+# Run everything except slow tests
+pytest -m "not slow"
+
+# Run performance tests only
+pytest -m performance
+```
+
+### Run by Directory
+```bash
+# Run all unit tests
+pytest tests/unit/
+
+# Run all integration tests
+pytest tests/integration/
+
+# Run API endpoint tests
+pytest tests/integration/api/
+
+# Run service layer tests
+pytest tests/unit/services/
+```
+
+### Run Specific Files
+```bash
+# Run specific test file
+pytest tests/unit/services/test_product_service.py
+
+# Run multiple specific files
+pytest tests/unit/services/test_product_service.py tests/unit/utils/test_data_processing.py
+```
+
+### Run Specific Tests
+```bash
+# Run specific test class
+pytest tests/unit/services/test_product_service.py::TestProductService
+
+# Run specific test method
+pytest tests/unit/services/test_product_service.py::TestProductService::test_create_product_success
+
+# Run tests matching pattern
+pytest -k "product and create"
+pytest -k "test_create_product"
+```
+
+## Advanced Test Options
+
+### Coverage Reporting
+```bash
+# Run with coverage report
+pytest --cov=app
+
+# Coverage with missing lines
+pytest --cov=app --cov-report=term-missing
+
+# Generate HTML coverage report
+pytest --cov=app --cov-report=html
+
+# Coverage for specific modules
+pytest --cov=app.services --cov=app.api
+
+# Fail if coverage below threshold
+pytest --cov=app --cov-fail-under=80
+```
+
+### Output and Debugging
+```bash
+# Show local variables on failure
+pytest --tb=short --showlocals
+
+# Stop on first failure
+pytest -x
+
+# Stop after N failures
+pytest --maxfail=3
+
+# Show print statements
+pytest -s
+
+# Show warnings
+pytest -W error
+
+# Capture output (default)
+pytest --capture=sys
+```
+
+### Test Selection and Filtering
+```bash
+# Run only failed tests from last run
+pytest --lf
+
+# Run failed tests first, then continue
+pytest --ff  
+
+# Run tests that match keyword expression
+pytest -k "user and not admin"
+
+# Run tests modified since last commit
+pytest --testmon
+
+# Collect tests without running
+pytest --collect-only
+```
+
+### Performance and Parallel Execution
+```bash
+# Show 10 slowest tests
+pytest --durations=10
+
+# Show all test durations
+pytest --durations=0
+
+# Run tests in parallel (requires pytest-xdist)
+pytest -n auto
+pytest -n 4  # Use 4 workers
+```
+
+## Test Environment Setup
+
+### Database Tests
+```bash
+# Run database tests (uses test database)
+pytest -m database
+
+# Run with test database reset
+pytest --tb=short tests/integration/database/
+```
+
+### API Tests
+```bash
+# Run API endpoint tests
+pytest -m api
+
+# Run with test client
+pytest tests/integration/api/ -v
+```
+
+### Authentication Tests
+```bash
+# Run auth-related tests
+pytest -m auth
+
+# Run with user fixtures
+pytest tests/integration/security/ -v
+```
+
+## Configuration Options
+
+### pytest.ini Settings
+Our `pytest.ini` is configured with:
+
+```ini
+[pytest]
+# Test discovery
+testpaths = tests
+python_files = test_*.py
+python_classes = Test*
+python_functions = test_*
+
+# Default options
+addopts = 
+    -v
+    --tb=short
+    --strict-markers
+    --color=yes
+    --durations=10
+    --cov=app
+    --cov-report=term-missing
+    --cov-report=html:htmlcov
+    --cov-fail-under=80
+
+# Custom markers
+markers =
+    unit: Unit tests
+    integration: Integration tests
+    # ... other markers
+```
+
+### Environment Variables
+```bash
+# Set test environment
+export TESTING=true
+
+# Database URL for tests (uses in-memory SQLite by default)
+export TEST_DATABASE_URL="sqlite:///:memory:"
+
+# Disable external API calls in tests
+export MOCK_EXTERNAL_APIS=true
+```
+
+## Common Test Scenarios
+
+### Development Workflow
+```bash
+# Quick smoke test (unit tests only)
+pytest -m unit --maxfail=1
+
+# Full test run before commit
+pytest -m "unit or integration"
+
+# Pre-push comprehensive test
+pytest --cov=app --cov-fail-under=80
+```
+
+### Debugging Failed Tests
+```bash
+# Run failed test with detailed output
+pytest --lf -vv --tb=long --showlocals
+
+# Drop into debugger on failure (requires ipdb)
+pytest --pdb
+
+# Run specific failing test in isolation
+pytest tests/path/to/test.py::TestClass::test_method -vv -s
+```
+
+### Performance Testing
+```bash
+# Run performance tests only
+pytest -m performance --durations=0
+
+# Run with performance profiling
+pytest -m performance --profile
+
+# Load testing specific endpoints
+pytest tests/performance/test_api_performance.py -v
+```
+
+### CI/CD Pipeline Tests
+```bash
+# Minimal test run (fast feedback)
+pytest -m "unit and not slow" --maxfail=5
+
+# Full CI test run
+pytest --cov=app --cov-report=xml --junitxml=test-results.xml
+
+# Security and integration tests
+pytest -m "security or integration" --tb=short
+```
+
+## Test Reports and Output
+
+### Coverage Reports
+```bash
+# Terminal coverage report
+pytest --cov=app --cov-report=term
+
+# HTML coverage report (opens in browser)
+pytest --cov=app --cov-report=html
+open htmlcov/index.html
+
+# XML coverage for CI
+pytest --cov=app --cov-report=xml
+```
+
+### JUnit XML Reports
+```bash
+# Generate JUnit XML (for CI integration)
+pytest --junitxml=test-results.xml
+
+# With coverage and JUnit
+pytest --cov=app --cov-report=xml --junitxml=test-results.xml
+```
+
+## Troubleshooting
+
+### Common Issues
+
+#### Import Errors
+```bash
+# If getting import errors, ensure PYTHONPATH is set
+PYTHONPATH=. pytest
+
+# Or install in development mode
+pip install -e .
+```
+
+#### Database Connection Issues
+```bash
+# Check if test database is accessible
+python -c "from tests.conftest import engine; engine.connect()"
+
+# Run with in-memory database
+pytest --override-db-url="sqlite:///:memory:"
+```
+
+#### Fixture Not Found
+```bash
+# Ensure conftest.py is in the right location
+ls tests/conftest.py
+
+# Check fixture imports
+pytest --fixtures tests/unit/
+```
+
+#### Permission Issues
+```bash
+# Fix test file permissions
+chmod +x tests/**/*.py
+
+# Clear pytest cache
+rm -rf .pytest_cache/
+```
+
+### Performance Issues
+```bash
+# Identify slow tests
+pytest --durations=10 --durations-min=1.0
+
+# Profile test execution
+pytest --profile-svg
+
+# Run subset of tests for faster feedback
+pytest -m "unit and not slow"
+```
+
+## Integration with IDEs
+
+### VS Code
+Add to `.vscode/settings.json`:
+```json
+{
+    "python.testing.pytestEnabled": true,
+    "python.testing.pytestArgs": [
+        "tests",
+        "-v"
+    ],
+    "python.testing.cwd": "${workspaceFolder}"
+}
+```
+
+### PyCharm
+1. Go to Settings → Tools → Python Integrated Tools
+2. Set Testing → Default test runner to "pytest"
+3. Set pytest options: `-v --tb=short`
+
+## Best Practices
+
+### During Development
+1. **Run unit tests frequently** - Fast feedback loop
+2. **Run integration tests before commits** - Catch interaction issues  
+3. **Check coverage regularly** - Ensure good test coverage
+4. **Use descriptive test names** - Easy to understand failures
+
+### Before Code Review
+1. **Run full test suite** - `pytest`
+2. **Check coverage meets threshold** - `pytest --cov-fail-under=80`
+3. **Ensure no warnings** - `pytest -W error`
+4. **Test with fresh environment** - New terminal/clean cache
+
+### In CI/CD
+1. **Fail fast on unit tests** - `pytest -m unit --maxfail=1`
+2. **Generate reports** - Coverage and JUnit XML
+3. **Run performance tests on schedule** - Not every commit
+4. **Archive test results** - For debugging and trends
+
+---
+
+Need help with a specific testing scenario? Check our [Testing FAQ](testing-faq.md) or open a GitHub issue!
\ No newline at end of file