If you’re thinking of PayPal, I think you are at least partially wrong on that: he didn’t start that one either but another company that was not that successful… I want to say he bought the more successful company and kept that name, merging his into it, and tried to do a lot of his own software engineering on it that was so bad they had to rip all of it out when they ousted him for how badly he was managing the company.

This could be misremembered as well though, but I don’t think he actually has a single successful company he can legitimately claim the title of “founder” of without having bought the rights to call himself that when he bought the company.