And that's to say nothing of figuring out things like accounting, bookkeeping, GDPR / regulations... And when you hire employee(s)... payroll, HR systems, G Su

And that's to say nothing of figuring out things like accounting, bookkeeping, GDPR / regulations... And when you hire employee(s)... payroll, HR systems, G Suite (it's a monster, but you must master it), recruiting / hiring platforms, And once you raise money... cap table management software, contracts galore, investor relations, boards meetings, etc. (On a completely unrelated note: all of the above is the reason YC and others usually have a bias against funding solo founders. Simply put, there's a lot that goes in to running even a small startup, beyond just building product.)