Part 4: gRPC Internal & REST Gateway: API Contract Lifecycle
Prerequisite: This is the starting part of the series — no prior part is required. Later parts assume the concepts introduced here. Answer-first: Combining internal gRPC transport with an automated REST JSON Gateway (grpc-gateway) provides sub-millisecond HTTP/2 inter-service RPC performance while exposing standard OpenAPI/REST endpoints to web/mobile clients, guaranteed through Protocol Buffer contract linting and backward-compatible schema versioning. The sequence diagram below illustrates the end-to-end request lifecycle as an external REST/JSON HTTP client payload is transcoded by the API Gateway into high-performance gRPC Protobuf binary calls across internal microservices. ...