I suspect the CEO makes somewhere in the area of a million a year. The AWS services alone probably cost a fortune. AWS is Amazon Web Services, which charges for scaled web deployment. You also need to cover rent costs in that expensive piece of SF real estate. You need to pay a pretty good fee to Cloudflare (most likely) for security and authentication cloud management. You need to pay the writers they partner program payments.

I am quite confident that Medium is not making a profit, and if it is, just barely.