gRPC vs REST for Microservices — When to Use Each and Why I Chose gRPC

I've built microservice systems with both REST and gRPC. The answer isn't one-size-fits-all — it depends on who's calling and what you care about.

Where gRPC wins

Internal service-to-service communication is where gRPC shines. Strongly typed contracts via Protobuf, generated client code in any language, and binary serialization that's 5–10x smaller than JSON. For Unirift's 9 services communicating internally, this was the obvious choice.

Where REST still wins

Public APIs and browser clients. gRPC-Web exists but adds complexity. If you're building a public API that third-party developers will consume, REST with OpenAPI docs is still the better DX.

The buf toolchain

Raw protoc is painful. buf handles linting, breaking-change detection, and code generation with a clean config file. It's the difference between gRPC being pleasant and gRPC being a chore.