The code is necessarily in different places, whether it's within a project or between projects. The difference is having an API that can be found without having to read all the code, and is well-defined and somewhat stable.
It's very "UNIX" to implement things as communicating processes rather than RPC or procedure-call-within-monolith.
It's very "UNIX" to implement things as communicating processes rather than RPC or procedure-call-within-monolith.