Classic version control:

@grumpygamer this is how id software developed DOOM.

I don’t remember which one of them but they did a very interesting talk about the development process. It’s on YouTube somewhere. Possibly https://m.youtube.com/watch?v=eBU34NZhW7I but I can’t verify that right now. Watched it years ago.

DOOM’s Development: A Year of Madness

YouTube
@xexyl I'm sure they did. There were no VCS options back then.
@grumpygamer precisely. The talk is quite fascinating probably more so if you played the game. It was very much more than just revision control.