api-builder

Choose FastAPI for high-concurrency microservices and ML APIs where native async support matters. Choose Django when you need a full-featured application with a built-in admin panel, ORM, and batteries-included conventions for SaaS or e-commerce projects.

Use python-jose or pyjwt to encode access tokens with short 15-minute expirations and refresh tokens lasting 7 days. Validate tokens in a dependency that decodes the Bearer token, extracts the user ID, and loads the user from the database.

Use select_related for foreign key relationships and prefetch_related for many-to-many fields in your ViewSet get_queryset method. This collapses per-object queries into a constant number of database round trips.

Yes, FastAPI generates OpenAPI specifications and interactive Swagger UI documentation automatically from your route signatures and Pydantic models. You can enrich it with examples, error responses, and authentication flow descriptions.

Provide /health/live for liveness probes, /health/ready for readiness checks that verify database and Redis connectivity, and /metrics for Prometheus scraping. Kubernetes uses these to manage pod lifecycle and traffic routing.

Implement a token bucket or sliding window algorithm backed by Redis, keyed by client IP or user ID. Return HTTP 429 with a Retry-After header when limits are exceeded, and apply tiered limits based on the user's plan.