[barrkel]

I found gRPC not particularly fast on a per-message basis unless you're using the streaming feature. If you have iterated calls, consider streaming instead.

Because it supports full duplex streaming, there's a risk of tunneling your own less than fully specified protocol on top of gRPC. In some circumstances that may be worth taking advantage of, because gRPC takes care of session management, reconnecting, authorization (i.e. it has ways for you to add authorization, like headers) etc.

If you need queuing I think you should use a queue instead.