That’s the recruiter’s job, not the interviewing engineer’s. Once a candidate gets time with an engineer, the assumption should be that they are at least kind of good, and not an outright fraud. A good enough fraud might get through this, but a genuinely good engineer might not get through the nano questions.

I never had any success working with recruiters. I have only had success when doing everything from screening CV’s to the end. I think having a ”chain” with HR, Recruiters etc is an antipattern.