DRPC: A battle-tested, drop-in replacement for gRPC in under 3kloc (opens in new tab)

The biggest problem from what I've experienced is Protobuf, not really gRPC.

Even though gRPC works fine overall, of course a simpler, faster implementation is always welcome.

But having used Capn Proto, I would reach for that rather than Proto if starting clean slate. It's much more flexible and expressive. If your language has good support, that is.

Another proto based RPC framework with code generators mainly for Go that also explicitly says it's simpler than gRPC is Twirp from Twitch: https://github.com/twitchtv/twirp

I haven't used any of the two yet though so I can't comment on their differences.

Strange to me that a blob intensive service (storage) would do a greenfield implementation of an RPC framework using protobuf, which is pretty bad at encoding blobs efficiently (and trashes a lot of memory).

I'd expect such an endeavor to pick something like Google's Flatbuffers, Apache Arrow or something similar. Although to be fair, I'm also guilty of having far more experience with protobuf than other formats.