thirty minute OA for fifteen questions. Stuff about probability like combinatorics, bayes rule, markov chains, et cetera. Also one question about t-test. Takes a while to get back after OA.
Interview questions [1]
Question 1
What is the probability the coin is biased (always heads) given seeing 5 heads in a row
I interviewed at Citadel Securities (New York, NY)
Interview
Three stages. Timed online assessment on probability, combinatorics, mental math, and estimation. Short recruiter call on fit and motivation. Virtual onsite with several 30 to 45 minute rounds on market making, risk reward tradeoffs, brainteasers, data interpretation, and teamwork. Decision in about a week.
Interview questions [1]
Question 1
Three stages. Timed online assessment on probability, combinatorics, mental math, and estimation. Short recruiter call on fit and motivation. Virtual onsite with several 30 to 45 minute rounds on market making, risk reward tradeoffs, brainteasers, data interpretation, and teamwork. Decision in about a week.
Applied online. Once past the resume screen, there were 2x phone screens, which if you passed, was followed by a final round superday. Superday consisted of group questions as well as individual questions.
I applied online. I interviewed at Citadel Securities in Aug 2025
Interview
started with an online assessment and then first round was like brain teasers and then the second is harder probability question and then it’s a super day and then you get the offer