I meant the interfaces are horrible. As you said, as long as it has a good interface and good performance, I wouldn't mind.

For example, here's the official tutorial for using the async callback interfaces in gRPC: https://grpc.io/docs/languages/cpp/callback/

It encourages you to write code with practices that are quite universally considered bad in modern C++ due to a very high chance of introducing memory bugs, such as allocating objects with new and expecting them to clean themselves up via delete this;. Idiomatic modern C++ would be using smart pointers, or go a completely different route with co-routines and no heap-allocated objects.

ouch. I'm temped to look up the protocol and build my own grpc implementation from scratch. Generated code isn't that hard to create, but it is something I'd expect to be able to just use someone else's version instead of writing (and supporting) myself.