I'm waist-deep in Express and Node stuff and I can feel the water climbing. I can't swim. This is a concern.
Long story short, I'm at the "oh no, how did I manage to put all the things into one ungodly file" stage of handling inputs and prepping outputs. I mean, despite even using a bit of underscore back there. After a moment or two of Google despair (so many tutorials that seem to assume you want to do nothing more than immediately send the user a "Hello world" response), I found this post by Alex Sears, which, at least right now, feels like an excellent primer on how to do some of the bad things I've done much, much better.