I don't think "interchangeable" is the right word here. In some cases, perhaps, but different languages have different idioms and, since you have Clojure on th

I don't think "interchangeable" is the right word here. In some cases, perhaps, but different languages have different idioms and, since you have Clojure on there, different paradigms. If the individual coming into the new language is diligent about learning how to properly work in it, then all is well. If they decide to try and force what they already know into the new language, that is problem. I've experienced the latter far more often than the former. If you're working for a feature factory, though, I guess it doesn't matter.