On top of that, Carmack was essentially the singular engineer on his projects. Most others were concerned with making levels, assets, music, etc. There were others (sorry Abrash and Cash) in the codebase but it was largely John. Which means his bus factor was insanely high. He was the definition of a silo of knowledge. He also used this to his advantage, knowing the company could not replace him. Most projects of a certain size cannot and do not want that dynamic. It is not a healthy dynamic once there’s some number of people working in close proximity.

I'd say most of us do not have this kind of focus. He actually has two focuses: strategic focus and tactical focus. Strategic focus means that he devotes a good part of his life into building a virtual world and concentrates on rendering algorithms. Tactical focus means that he can work 10+ hours daily for every day for a large part of his life.

Most of us would be lucky to get a quarter of those two focuses.

I currently work every day on a codebase that is >95% not mine and changing, and its very fun. Some days I'm just as productive as on my own projects, sometimes 1% of that.

I think there is great value in letting yourself enter this hacker flow state on other people's code - its new and exciting.

Glad to see this, I'm a mega John fanboy as they come but the reality is this is close to the ideal working env for a hacker of his talents. The single biggest hurdle to good code is somebody else touching it and the other major hurdle is not owning the company/product direction.

Again, I am happy to recognize him as a genius no doubt, but I couldn't imagine he would've lasted in a CRUD Java gulag. Those places... break people.