having just gone through that, my pro tip is: look at implementing promise.all() as well as extending the code to have a limit on concurrent promises/etc. very popular question.
Basically all the things you otherwise forget about or never need to worry about when writing production JavaScript. Yawn. I sound like a curmudgeon and I am: too many interviews I've been in that involved JavaScript felt like abstracted garbage. Nevertheless, good luck!
How people answer questions around promises in general often gives me a good idea of where they are at in their JavaScript journey.