Have you worked with gRPC? What protocol is used under the hood?

Yes, I have worked with gRPC. Under the hood, gRPC uses the HTTP/2 protocol for message transport. This provides efficient bidirectional streaming, request multiplexing, and low latency.

gRPC uses Protocol Buffers (protobuf) for data serialization, which allows for compact and fast message transmission between client and server.

Thus, gRPC combines HTTP/2 as the transport protocol and protobuf as the serialization format, ensuring high performance and ease of development of distributed systems.