depends on your definition of rich
$1m/yr
If you want to remain an employee maybe some hedge fund / investment bank quants ? A (senior) partner at mckinsey ? something like that maybe ?
But yeah, 1m/yr is hard if you don't own stakes in the business. And if you make that much as a partner at mc or EY for instance, it's because you have boughts shares of the firm when entering the partnership and that you've worked looong hours for over a decade.
Maybe being super high up at big tech firms through earned stocks ? Well, once you've had a high position at a big tech firm, you can easily go into consulting / start doing conferences and start making real cash. But that'll hardly be before 35-45 years old I don't think.
Ok, so what path has the least resistance for getting rich for a skilled developer?