Backend
API Design
Design high-quality REST, GraphQL, and gRPC APIs with contract-first workflows, resource modelling, versioning, pagination, error contracts, and OpenAPI authoring. Use when designing a new API, reviewing an existing API contract, defining error schemas, choosing between REST / GraphQL / gRPC, or writing an OpenAPI specification. Triggers: "API design", "REST API", "OpenAPI", "swagger", "versioning", "pagination", "error contract", "gRPC", "GraphQL", "contract-first", "resource model", "API review", "HTTP API".