OP here. Agree completely that .proto offers big advantages on its own. Also agree that grpc is complex and challenging. We considered twirp too. A few thing

OP here. Agree completely that .proto offers big advantages on its own. Also agree that grpc is complex and challenging. We considered twirp too. A few things that pushed us towards gRPC... Canonical error codes and semantics. Standards here go such a long way to building reliable systems. The ecosystem. There are a lot of middlewares, validators, transcoders written specifically for the Go gRPC stack. Envoy. This has a lot of things we wanted like rate limiting and auth which are implemented over gRPC. With AWS adopting Envoy for their service mesh offering it’s a safe technology bet now. Performance. This doesn’t matter for our API stack but could be a huge gain in Segments data plane. That said I still wish all this was simpler. Twirp looks like a great choice in that regard.