My reasons for leaving Apple had nothing to do with this decision. I was already no longer working on Rosetta 2 in a day-to-day capacity, although I would still frequently chat with the team and give input on future directions.

Just went through that thread, I can't believe this wasn't a team of like 20 people.

It's crazy to me that apple would put one guy on a project this important. At my company (another faang), I would have the ceo asking me for updates and roadmaps and everything. I know that stuff slows me down, but even without that, I don't think I could ever do something like this... I feel like I do when I watch guitar youtubers, just terrible

I hope you were at least compensated like a team of 20 engineers :P

History doesn't repeat, but it does rhyme: the initial (re)bootstrapping of OS X for Intel was done by one person, too.

https://www.quora.com/Apple-company/How-does-Apple-keep-secr...

Sometimes (often?), one very dedicated and focused person is better than a team of 20+. In fact companies would do well to recognize these situations and accommodate them better.

Found some gems buried in the comments:

    > Back then, Apple had a sabbatical program that encouraged (mandated?)     employees to take six consecutive weeks off every five years.
This is really a good take. I can't imagine companies give sabbatical programs nowadays. You still have your vacations so JK took 12 weeks (OP mentioned in the same comment). It was a boon for any system programmer who needs to clear his mind or deepen his thoughts.

This is amazing. I wonder what it took to port MacOS from PowerPC to Intel. Every assembly language part must be rewritten, that’s for sure. Anything else?

Didn't Nextstep support x86 long before MacOS X was a thing? I assumed that they always had it compilable on x86 long before the switch (since Rhapsody supported it). I guess the user space stuff might have been trickier but probably not the kernel itself and surrounding components.

Yeah but from what I read from the Quora answer, it sounds like JK did it from scratch? I could be wrong though. I just wonder how much effort is supposed to be put into such a project.

Likely a few foundational technologies that have had significant improvements/reimplementations from Rhapsody like the scheduler/threading infrastructure, memory management, Quartz, Carbon, Quartz.

I think a single 10x developer is really good for this kind of system programming projects.

Thank you for your work!

Thank you for the clarification!