API Design and Implementation Questions

Design and implement application programming interfaces and the server side request handling required for production services. Topics include resource modeling and endpoint design, representational state transfer versus remote procedure call systems and when to choose each, HTTP method semantics and status codes, pagination and cursor strategies, versioning and backward compatibility, rate limiting and throttling headers, idempotency and exactly once processing approaches, request validation and middleware patterns, error response design and retry semantics, serialization formats and schema evolution, streaming endpoints, contract definition and interface tooling, security at the API boundary, monitoring and observability for APIs, and trade offs between public internet facing APIs and high performance internal RPCs.