A production API should include environment-based configuration, secrets management, structured logging, request IDs, health endpoints, graceful shutdown, timeouts, validation, rate limiting, secure headers, dependency monitoring, metrics, tracing, automated tests, and deployment automation.

Never place secrets directly in source code. Never expose internal stack traces to clients. Do not assume process-level memory is durable or shared across replicas.

A production-ready API is not defined by the number of endpoints. It is defined by predictable behavior under valid input, invalid input, high load, partial failure, and malicious input.