First round: A written test on link lasting for 15 days. A 90-minute math section consisting of 6 questions, including topics such as linear algebra, probability statistics, etc. (Forgot to mention PDE, seems like it's not included; you can refer to past experiences if available). Second round: Initial interview covering CV research/internship experiences. On-site, there will be brainteasers/mathematical questions, and a two-week project will be assigned to predict returns. Third and subsequent rounds: 2-3 interview rounds. The first round involves 3-4 junior researchers asking questions related to brainteasers, advanced math, statistics, machine learning, and engineering (project-related). Knowledge of finance is a plus. The second round is an interview with senior researchers, similar in content but more challenging. The third round (if applicable) may involve a small leader interview.