> And it did it in <10 minutes. The best candidate I ever saw took 25 minutes and the rest of the candidates took the full allotment of time 45 minutes and none of them got to the discussion of L2 cache optimization. These are candidates from the best schools in the country.

I'm not surprised. It's something that's covered very well by introductory textbooks and college level labs. Both of which are great training material for GPT-3. There's only so much complexity that can be crammed into a ~1 hour interview problem.