I don't think it's recent, as far as I know. Versioning, appup / relup, etc. are really for upgrading production deployments live, when you need special instruc

I don't think it's recent, as far as I know. Versioning, appup / relup, etc. are really for upgrading production deployments live, when you need special instructions to pause processes or update their internal state before loading new code. In development, you can ignore all that and just reload modules directly. e.g. with "r" in the Elixir REPL. Once that's done any external call (`MyModule.add(1,2)`) will go to the new version of the code, while local calls (`add(1,2)`) stay on the same version. The Phoenix web framework will also auto-reload any module that has changed on disk when handling a web request in dev mode.