[dmoy]

> AFAIK they have a bunch of production infra on protobuff/gRPC

Stubby, not gRPC. Stubby is used for almost everything internally. gRPC is a similar-ish looking thing that is open sourced, but not used nearly as much as stubby internally.

Stubby predates gRPC by like 15 years or something.

> not so sure about flatbufferrs which came out of the game dev side

I wouldn't know. I'll be honest, I always forget that Google made flatbuffers. I guess if you're doing a lot of IPC?