Comment by acdha
The way these people are being caught are things like dodgy LinkedIn profiles or refusing in person meetings so I would think a licensing process designed around things which would be expensive to fake: in person government ID checks, periodic exams, peer evaluations, etc. The trick would be actually doing that in person, which could be a useful thing for conferences - treat an afternoon at PyCon or re:Invent as the cost of renewing your professional credentials if you don’t live near a major city or university.
Even an in person ID check would suffice.
For most of the West, this is an extremely difficult bar to clear for a North Korean national working out of China.