Oh yeah; this was the best part of moving to Erlang/OTP... Test suites are absurdly fast (nearly) all the time. Most test suites I use take less than 10 seconds with anywhere from 100-1000 unit tests. The worst I've seen "monoliths" take at most ~90 seconds to run and that is only ever the case if folks are creating insanely too many objects or needlessly testing the internals of `gen_server`.