Ask HN: What year did algorithm-focussed interviewing begin?
I've speculated that the transition is due to Google having been founded by a couple of grad students. When I was a graduate student in Physics, a dreaded rite of passage was the so-called "Comprehensive Oral Exam," at which you were expected to be able to know and derive on the spot anything taught in the entire undergraduate-level canon. Perhaps the founding grad students did not have any other model for an effective interview process, and simply adopted the only thing they were familiar with. Google became successful, everyone else copied them, and here we are...