Citadel Securities Quantitative Researcher (Intern) interview questions

the discussed topics themselves are very broad and include anything from your past research to open-ended questions on stats/dl/games; I had 6 rounds but usually folks have 5 to 7 of them, depends on the number of teams that are interested in u; all interviews were recommended to be finished in 40 minutes, but we managed to chat with interviewers for 10-20 minutes after the technicals; the staff was kind and the process itself more resembled some type of informal and pretty chill chat