Author of the article here and just came across this comment. Here's how I did it. By working at Uber in Amsterdam for 4 years where I made more than twice as much as a senior engineer as I did before when I was at Skyscanner, in London where I was a principal engineer.

Saved the difference and I had about 3-4 years of savings. Decided to "risk" 6 months of it and dip into it.

https://twitter.com/GergelyOrosz/status/1552615944446525442