I'm not sure that's sufficient reason to say that config files are preferable to environment variables. Presumably the config file would be kept separately from

I'm not sure that's sufficient reason to say that config files are preferable to environment variables. Presumably the config file would be kept separately from the project code, so it doesn't reduce deployment complexity. Furthermore, environment variables work with basically every programming language and tool you're liable to use without modification. I don't think using config files is a bad solution, it just isn't categorically better because some programs have been written to dump env vars on a crash.