My first job right out of college I was writing assembly for some epically old industrial equipment. That shit runs on its own language that was only ever used on that piece of equipment. Usually x86 but with some wacky modifications. There's no compiler for that, just a manual the size of a textbook and a million chicken scratch notes in it that's half covered in grease. I'm so glad I don't do that anymore.

Same. I participate on web game jams for fun.