Ask HN: Did your side projects ever become something big enough to sustain you?

Yeah! I worked on a baby book, Computer Engineering for Babies (https://hackylabs.com), for about 5 years before I launched it on Kickstarter back in 2021. It has two buttons and an LED to illustrate various boolean logic gates. The project surpassed all expectation, and I quite my job a year and a half later. I've launched 2 other books since then, and I'm working on a fourth.