good question… thinking back to pre-LLM interviews I experienced （before 2019）… they were all in-person on-site， no chance of ''llm cheating，'' very different across places， and somehow way more memorable.

old deepmind had brutal ''quizzes'' -- 2-hour marathons with 100+ math/stats/ML concept questions.

meta FAIR was basically academia interview with a bit of coding， but the highlight was chatting vision research with piotr， ross and kaiming.

google brain/research was similar. the @NoamShazeer was my coding interviewer， who kindly kept it simple with just a two-pointer q. we spent most of the time discussing research， where I explained how I had applied something called a transformer to visual data （point clouds） -- a topic that， at the time， hardly anyone cared about.

but the coolest？ openai in 2018： whiteboard coding， a research talk， and a *~5-hour* session in a tiny room to work on an RL problem （variance collapse in cross entropy methods）. I knew almost nothing about RL， but that was the point. They handed you a self-contained problem description， handwritten by @johnschulman2， and expected you to learn， research， solve， write up in a notebook， and present.