We've begun to use Elixir and Phoenix at work, and it's far nicer to work with than Rails - there's far less magic going on, and being functional, there is much less mutable state to keep in your head. That said, I still miss a rich type system. Typespecs can get you some of the way, but they're unreliable, and there's no support for parametrically polymorphic functions so far as I can see, which limits the usefulness of protocols for typechecking purposes.