Theoretically you could use gRPC with JSON or Flatbuffers or whatever rather than protobufs.
(I'm not sure how much practice there is behind that theory, currently, but that's the plan.)
(I'm not sure how much practice there is behind that theory, currently, but that's the plan.)
I for one am glad they didn't go towards custom protocols with single complex implementations, towards something that can be assembled easily from standard components.