Obvious candidates:
-Satoshi Nakamoto (if he is actually a single person)
-Early Google engineers
https://en.wikipedia.org/wiki/Markus_Persson
And more recently:
Tom Preston-Werner / mojombo - Founder of GitHub ($1.25BN)
- https://en.wikipedia.org/wiki/John_Carmack - https://twitter.com/ID_AA_Carmack
He might not be a 10+ digit billionaire but he's likely at least a 9 digit millionaire.
To have $1bn and still code full time, it would have to be 'hands off' money, which is rare because to make that much money you'd probably need a wildly successful business which you kind of need to manage yourself.
Someone else mentioned trading firms, that might be one way, with enough luck and negotiation skills.
Otherwise, I think becoming a billionaire while purely working on software is extremely unlikely, bordering on impossible. Billion-dollar net worths necessitate leading billion-dollar businesses, and those aren't made solely with code.
If not billions, I think it's fair to assume they're each worth several hundred million.
He has been a programmer for decades and is still active at it.
So, you have 4 layers:
- poor
- doing ok
- rich
- super rich ( > 1 billion)
Each generation can only go up 1 step. It's mostly that show because of social aspects.
And I don't think rich people or their children will be programmers. They will probably employ them.
Fyi, It's extremely rare that you can skip a step.