It's comical how the FA jumps right in assuming you know what it is, what it's for, and why you should care about the first two -- comical in a good way, for those of us who are happier not knowing.

I have a vague impression that Elixir has something to do with Erlang, and that is all I need to know, but that Phoenix has something to do with Elixir also wasn't mentioned right away.