gRPC — Part 4: Real-World Examples & Code Walkthroughs

What is this?

We've talked about the phone-extension idea, the HTTP/2-and-protobuf machinery, and how to defend the answers in an interview. Now let's build something. This part walks through one example per RPC type — a unary service, a server-streaming feed, a client-streaming upload, and a bidi chat — so the four modes from Parts 1 and 2 stop being abstract.

The one-line idea: every gRPC service starts the same way — write the .proto contract, generate the stub, then implement a handler that just reads typed objects and returns typed objects. The streaming mode you pick only changes how many messages flow in each direction; the shape of the code stays familiar.

Code here is trimmed to the load-bearing parts — the contract and the core handler logic — with the boilerplate (server bootstrap, metrics scaffolding) left out so the patterns stand out. Snippets are illustrative Python; the exact API varies by language.