Interesting. I’ve found in particular that using pure functions whenever possible has simplified testing a great deal. ES6/7 has made it much easier.
I’ve gotten a good number of opportunities to do Clojure work at my new job, which pleasantly surprised me.
When first jumping into it, not knowing how to do simple things like loops was a bit maddening. Then I figured out I rarely had to code them unless I was doing it for side effects.