In my experience, the “10x” developers are just doing their job.
Maybe we should focus on the dev/10 people, they just make people who are gitting stuff done look amazing.
The reality is a subset of engineers are just better, quicker and faster. They known things and can do things faster.
I have worked a verity of teams. However gross it is to you the person pulling in 30k of line of code in a complex system in 3 weeks is definitely something more than the average developer.
I know I know. Everybody is going now pile on with some crazy assumptions about code quality shit. Let me stop you. You were not there, the code was amazing and the code ran rock solid.
Also this was not a one off. Every project I worked with this person simply was the same way. 15 min sync, 3 days later amazing features, 90%+ unit test coverage, all while doing 9-5 and cooking dinner for her family after destroying that PR button.
So whatever you want to call them, they exist, and they are likely better than you in every metric you can measure.
Get over it do better.