That's really interesting. I've thought about trying to replace ROS with GRPC before too. I could never find a report of anybody actually doing that in the robotics space. Can you share more? How did it go? What pitfalls did you run into?
GRPC is very performant. A few points, ensure you have a script to compile the GRPC protobuf, ideally in docker so that you don’t pollute your local environment. That other pitfall, is don’t save raw protobuf binaries, you will face backwards compatibility issues as you change the definition of the protobuf, just write everything into MCAP’s. GRPC essentially replaces ROS messages with protobuf definitions and is not a publish, subscriber model, but you can build publisher/ subscribers out of it. It is managed by Google, used in android, web dev etc so it is very performant and reliable.