Except on StackOverflow all of those are unpaid voluntary community moderators. There are less than ten people being paid by SO in community facing positions as far as I know. Also, they recently fired two of their most long-standing community managers.

But StackOverflow (the company) is more than just public Q&A, and in fact public Q&A is not primarily how they make their money. Job ads and SO for teams seem to be the main revenue sources.