Just saying "gRPC over HTTP" doesn't solve any of the sentence you quoted. > common architectural backplane with well-understood integration and communication

Just saying "gRPC over HTTP" doesn't solve any of the sentence you quoted. > common architectural backplane with well-understood integration and communication conventions, whatever you want or need it to be Regardless of the tech used to implement, this paradigm needs to be solved to have a good system. That backplane is not an implementation, but a set of understood guiderails for inter-module communication. Even with gRPC, both sides need to know what to call and what to provide and expect in response. That's the "conventions" part. Having consistency is more important than the underlying tech. Just simple ReST over HTTP works just as well as gRPC.