Citadel has one of the highest turnover rates in the industry. Therefore they had to constantly interview people, just to keep with resignations. The interview process is very well managed, and efficient. They ask questions about your previous experience, some brain teasers and programming/algorithm questions. The questions are reasonable and thoughtful. You have to be very careful if they like you. They will try to convince you to join by lying to you about career prospects, job description, their "amazing" technology, good opportunities for advancement etc. Ignore the verbal garbage, and get everything in writing, assume nothing and carefully read everything you sign (read it twice and ask a lot of questions). They don't hesitate to lie and use dirty tricks to get you to accept offer with very nasty conditions.

- Questions on Linear Algebra and Coding - Discussion of a problem at the intersection of optimization and classical machine learning - No behavioural questions or anything about my personality or work experience, the interview was purely technical