First round: Self introduction + quick ask quick answer. Only 30~45 sec for each problem. There were 15 problems in total. Totally disaster but still move forward. Second round: kinda bad experience. The interviewer was late for about 10 mins. And he switched among laptop, conference room camera and phone. The question was about poisson process.

Five Rings’ Online Assessment 19 questions, 2 or 3 minutes. Tests mental math, estimation, combinatorics, quick logic, and probability intuition—very speed-intensive. After finishing OA, I received rejection within just 10 minutes.