[rojobuffalo]

Agreed. If you, as the interviewer, can't ascertain an applicant's ability to do the job, after chatting with them for an hour or two, you aren't qualified to hire for that position.

The idea that you can pinpoint someone's skill level (and estimate their performance potential) through additional hours-long exams is arrogant. Job performance has more to do with the environment than the incoming skill set.

When it comes to promotions, there was a paper this year that won an Ig Nobel prize, which made the case that promotions are awarded at worse-than-random https://arxiv.org/pdf/1802.07068.pdf