I made my first game, an implementation of Othello, when I was in high school, in BASIC on an Apple II+ (and then a 6502 assembly version that played really fast and incorrectly, and then a parallel processing version in college for my thesis), but I didn't work for a game studio until I was 35, started self-publishing on app stores in my 40s, and finally on Steam (and itch.io of course) in my 50s.