Backend Engineering with Django & FastAPI

The foundations every backend interview checks.

• HTTP methods, status codes, headers and cookies
• REST principles and resource design
• JSON, serialisation and content types
• DNS, TLS and what happens when you type a URL
• Testing APIs with Postman and HTTPie
• Statelessness, sessions and tokens

Build complete web applications with Django.

• Projects vs apps, settings and environment configuration
• URL routing and views (function-based and class-based)
• Models and the ORM: fields, relationships and querysets
• F and Q expressions, annotate and aggregate
• select_related and prefetch_related to kill N+1 queries
• Migrations
• Customising the Django admin
• Templates, forms and validation
• Static and media files

The parts that separate juniors from professionals.

• Authentication, permissions and a custom user model
• Middleware and signals
• Caching strategies
• Custom management commands
• File uploads and storage backends
• Settings for development, staging and production

Build clean, secure, well-documented REST APIs.

• Serializers: model, nested and custom validation
• APIView, generic views, ViewSets and routers
• Session, token and JWT authentication (SimpleJWT)
• JWT access and refresh tokens, rotation and blacklisting
• Permissions, role-based access and object-level permissions
• Pagination (page, limit-offset and cursor), filtering, search and ordering
• Throttling: anonymous, user and scoped rate limits
• API versioning and deprecation
• Consistent error responses
• OpenAPI documentation with drf-spectacular

Modern, async, type-safe APIs.

• Path operations; path, query and body parameters
• Pydantic v2 models and validation
• Dependency injection
• async/await and concurrency
• SQLAlchemy 2.0 ORM and Alembic migrations
• OAuth2 and JWT authentication
• Background tasks and WebSockets
• Streaming responses
• Middleware, CORS and automatic docs

Design data that stays fast at scale.

• PostgreSQL schema design and normalisation
• Indexes and reading EXPLAIN plans
• Transactions and isolation levels
• JSONB columns
• Redis for caching, sessions and rate limiting
• When MongoDB is the right choice

Move slow work out of the request cycle.

• Celery with Redis or RabbitMQ
• Scheduled jobs with Celery beat
• Retries, idempotency and dead letters
• Receiving and verifying webhooks
• Sending transactional email

Ship with confidence.

• pytest and pytest-django
• Fixtures and factories
• API and integration tests
• Mocking external services
• Coverage reports
• Linting and formatting with ruff; type checking with mypy
• pre-commit hooks

Protect users and data.

• OWASP API Security Top 10
• Authentication vs authorisation
• Password hashing and secret management
• CSRF, CORS, XSS and SQL injection
• Rate limiting and abuse prevention
• Safe file uploads

Add Generative AI features to a production backend.

• Calling LLM APIs from Django and FastAPI
• Streaming AI responses to the browser
• RAG search with PostgreSQL and pgvector
• Running AI work in background jobs
• Controlling cost, latency and rate limits

Take your code to production.

• Dockerfiles and docker-compose
• Gunicorn, Uvicorn and Nginx
• CI/CD with GitHub Actions
• Deploying to AWS (EC2 or ECS)
• Error tracking with Sentry and structured logging

Build a production-style SaaS backend end to end.

• Multi-tenant SaaS backend with auth, roles and billing-ready design
• Code review by a team lead
• System-design write-up
• Backend interview preparation