My main concern with node is how fast everything moves. Try to maintain a project that started with es5, then migrated to es6 (but some legacy code is still es5), then added some es2017 and now is adding slowly typescript to the monster, and all of this in just 3 years!

Things become a mess in no time, tooling changes constantly, and maintaining legacy code while developing new parts with current best practices helps you build a Frankenstein in no time.

(and don't even mention about coffee, or it'll make me start ranting about the move from coffee to es6 and now TS!)