But as soon as you do want to customize it, you’re stuck learning one of the most esoteric languages that wasn’t meant as a joke.

Doom barely ran on my Packard Bell 386

Windows on the front end and Linux on the backend isn’t uncommon these days. Big iron unix is expensive so it was largely moved off of, although there is still some Windows in the back end depending on vendor. I think Epic is Windows across all tiers.