Counterpoint on the "going all-in": we have a 7 year old Elixir/Phoenix project that currently sits at ~100K LOC and I couldn't be happier.

It has been absolutely wonderful building this with Elixir/Phoenix. Obviously any codebase in any language can become a tangled mess, but in 7 years we have never felt the language or framework were in our way.

On the contrary: I think Elixir (and Phoenix) have enabled us to build things in a simple and elegant way that would have taken more code, more infrastructure, and more maintenance in other languages/frameworks.