I've gotten the sense that the most common migration path is Ruby->Elixir. It seems that many of the people using Elixir previously used Ruby. The creator of Elixir was active in the Ruby world and Elixir has similar syntax to Ruby.

That said, I started getting into Elixir while doing C# and Javascript development, but I suspect that's a pretty uncommon path.

I don't think there are clear enough patterns; maybe that one is off by itself.