JavaScript/Node.js, Ruby, Elixir, Python and Java for the legacy.
That's what I am using at work. Doing the majority of my tasks in JavaScript.
I re-started Ruby since I have installed Gitlab last year and helped to migrate from SVN to Git. Gitlab is written in Ruby and adding stuff is fun or should I tell Ruby is fun again?!
Elixir I'm doing on side projects at work. Want to make it the primary language for the backend stuff, but some resistance at work is keeping me away from doing awesome things. But it was the same with JavaScript at work. I'll win, sooner or later :-)
Python and Java are only occasionally popping up, and I hope for even less, to be honest.