FastAPI

Workflow

1. Confirm product requirements, SLOs, and API contract expectations.
2. Define module boundaries: routers, domain services, and infrastructure adapters.
3. Establish lifespan-managed shared resources and request-scoped dependencies.
4. Enforce Pydantic request/response models as external contracts.
5. Choose correct async or sync execution paths for each endpoint.
6. Implement security, observability, and failure handling standards.
7. Validate with tests, load checks, and deployment-safe rollout controls.

Preflight (Ask / Check First)

• Check Python and FastAPI versions and runtime constraints.
• Check persistence stack and transaction requirements.
• Check whether endpoints are latency-sensitive, throughput-sensitive, or both.
• Check authn/authz model and compliance obligations.
• Check deployment platform, autoscaling behavior, and release cadence.