> ask to see their certificate and (if you're being particularly diligent) contact the school to verify it.

Certificates are ~useless in tech. I've encountered way too many candidates who have a bunch of certificates but don't actually understand anything they're supposedly certified in. They just memorized enough to pass the exam.

> Maybe it's possible to graduate from college with a CS degree without being able to solve fizzbuzz? So you need to check they can program despite their qualifications? IDK though.

Yes. It's astonishing how many CS grads simply don't understand programming.