Learn
Python and FastAPI Backend Engineering
Build testable APIs with dependency injection, async database boundaries, auth, background jobs, and production error handling.
Level: Intermediate. Track: Backend craft. Audience: Python developers who want professional API structure instead of tutorial-only endpoints.
Capstone: A modular FastAPI service with auth, repositories, rate limiting, tests, and deploy-ready observability.
Outcomes
- Design API boundaries with typed request and response contracts.
- Keep framework, domain, and persistence responsibilities separate.
- Ship a tested service with health checks, observability, and deployment notes.
Stack
- FastAPI
- Pydantic
- SQLAlchemy
- pytest
- PostgreSQL
Course sections
- API contracts and request boundaries — Turn endpoint sketches into explicit HTTP contracts with validation, status codes, and dependency boundaries.
- Production backend architecture — Move business work behind repositories, transaction boundaries, tests, and operational checks.
- Pro: operations and reliability — Make failures observable, workers safe, deploys repeatable, and runbooks useful to the next owner.
Professional roadmap
- Contract review ready — Document one endpoint family with schemas, status codes, and failure cases. Evidence: OpenAPI diff plus request examples for success and validation errors.
- Service boundaries in place — Move persistence and auth behind injectable providers. Evidence: Tests that override dependencies without touching production wiring.
- Deployable API — Package the service with tests, health checks, logging, and runbook notes. Evidence: A green test run and documented startup/readiness commands.
- Operable FastAPI service — Connect error contracts, request IDs, worker shutdown, deploy smoke checks, and rollback notes. Evidence: Correlation log sample, readiness output, worker shutdown proof, and deploy runbook.
Portfolio artifacts
- FastAPI service repository
- OpenAPI contract notes
- pytest integration suite
- Structured error contract
- Readiness and worker shutdown proof
- Deployment runbook
Lessons
- Routing and Validation Basics — Design a reviewable FastAPI contract with typed create/read schemas, explicit status semantics, validation evidence, route tests, and an OpenAPI drift check. 46 min.
- Advanced Dependency Injection — Design FastAPI dependency boundaries for request-scoped sessions, authenticated users, framework-free services, and test overrides that cannot leak between cases. 48 min.
- Repository and Unit of Work — Own a subscription billing write flow with product-language repositories, one explicit unit-of-work transaction, rollback proof, and routes that never reach through ORM details. 52 min.
- Testing, Packaging, and Operations — Package a FastAPI service so reviewers can prove route contracts, dependency overrides, startup commands, and liveness/readiness behavior before traffic reaches it. 54 min.
- Observability and Error Contracts — Design a FastAPI failure surface with stable ProblemDetails-style responses, request IDs, structured logs, bounded metrics, and a diagnostic playbook operators can actually follow. 56 min.
- Deploys, Workers, and Runbooks — Finish the FastAPI service with graceful worker shutdown, traffic-safe readiness gates, deploy smoke checks, rollback thresholds, and a two-minute handoff runbook. 58 min.
Canonical course URL