As a best-selling author, I invite you to explore my books on Amazon . Don't forget to follow me on Medium and show your support. Thank you! Your support means the world! Microservices need to talk to each other. The way they talk matters a lot. You have the most popular option, REST, where you send JSON over HTTP. That works, but it comes with a lot of weight. Your services have to parse text, agree on fields, and handle errors by hand. gRPC changes that. It uses Protocol Buffers to define a contract. You write a .proto file, and from that file you generate code for both the server and the client. The messages are binary, which makes them smaller and faster to process. The framework also gives you streaming, strong typing, and automatic retries. I have built several services this way, and the difference in speed and clarity is immediate. Let me start with the first technique. You define a shared contract in a .proto file. This file lives in a central repository, or you copy it to each service.…