If you're interested in using Elixir, jump right into Phoenix with LiveView. It is fantastic for prototyping new tools. Once you learn the basics of LiveView, it's ridiculously easy to create the web UI that interacts with your Elixir back-end.

For a while I was using Phoenix<>Elm as my stack and I enjoy programming in Elm. But there's a lot of boilerplate you have to tediously connect for every input and output on both sides of the server and client.

LiveView eliminates all that boilerplate by letting you write templates in Elixir that are macro-compiled to javascript. Getting rid of that boilerplate eliminates time writing it as well as time debugging the extra complexity that boilerplate introduces.