[relistan]

Author here. I know all about POSIX IPC (nearly 30 years UNIX admin here). It's not supported on the BEAM in a sensible way. Not to mention that if it were implemented, it would almost certainly violate the sensible failure domain management of the Erlang/BEAM ecosystem and OTP.

As for GRPC: we don't use it anywhere else. So we'd have needed all of the tooling on two stacks, calling patterns without native error handling that we'd have had to implement, and instead we have a thin wrapper that allows the Elixir app to call Go like native Elixir code. GRPC would have been worse in almost every way.