Is the $600k salary, bonuses, stock options or? Sounds quite incredible to me. I haven't heard from any dev making this kind of salary, not even in the big companies.
If it's in the form of options, you'll forgive me if I treat that as pretend money until it's transformed into real wealth.
And you're getting, on average, what, 400-500k a year in RSUs vesting?
Am I wrong is that basically bonkers as far as compensation goes? That feels at least a few standard deviations outside the mean... Which is great for you, and congratulations!
But "win the lottery" doesn't make for very compelling early retirement advice. :)