While working with Protobuf message format for one of my client projects, I recently came across a gRPC framework. After doing my analysis, gRPC seems pretty promising for inter-service communication, particularly in microservices architectures. gRPC is a language-agnostic, high-performance Remote Procedure Call (RPC) framework.
gRPC is built on top of the HTTP/2 transport layer and therefore can support four types of gRPC methods (unary, client streaming, server streaming, and bi-directional streaming). It uses Protobuf for message exchange.