That's related to something I realized which I think a lot of people might find amazing. They think of companies like Apple and Microsoft as trillion-dollar, globe-spanning companies, so it must be massive teams that work together on everything.

But no, read Hacker News or other niche places enough and eventually you realize a lot of the things we all know or use was a solo effort or a very small number of people, sometimes not even an assigned project but something they did on the side. Cue the xkcd about the lone open source project maintainer holding up the entire modern web but apply it to the tech giants and there you go, it happens there too.