Claude 4.6 has been excellent with Go, and truly incompetent with Elixir, to the point where I would have serious concerns about choosing Elixir for a new project.
Before we continue, the following opinion comes with several important caveats:
1. It only applies to paid professional work. If it's a hobby project, choose whatever makes you happy.
2. It ignores the strengths and weaknesses of different languages. These may outweigh any LLM-related concerns.
3. This is my opinion today. I _think_ it will survive longer than the next LLM cycle, but who knows these days.
4. May contain nuts.
Okay, that's the ass-covering dispensed with, on to the opinion:
If the choice is between a language which is "LLM friendly" (for want of a better phrase) and one which is not, it is irresponsible to choose the latter.
Opus and Sonnett practically writes the same idiomatic elixir (phoenix, mind you) code that I would have written myself, with few edits.
It's scary good.
https://autocodebench.github.io/