gRPC Deep Dive

gRPC is a contract-first RPC framework built around Protocol Buffers and HTTP/2. A .proto file defines the service. Code generation produces typed clients and server interfaces in every supported language. Calls carry deadlines, cancellation, metadata, structured status codes, and optional streaming.

Service-to-service APIs fail in different ways than public web APIs. The caller and server are usually deployed by the same organization, latency budgets are tighter, request rates are higher, and a small contract mismatch can break an entire request path. REST and JSON remain excellent defaults for many systems, but for internal APIs with strict contracts, high call volume, streaming, and services in several languages, REST leaves too much to convention.

gRPC is strongest when you control both sides of the API and can afford the operational discipline that comes with generated contracts. It is not a default replacement for REST at the edge.