Quant Trading applicants have rated the interview process at Citadel Securities with 4 out of 5 (where 5 is the highest level of difficulty) and assessed their interview experience as 100% positive. To compare, the company-average is 53.9% positive. This is according to Glassdoor user ratings.
Here are the most commonly searched roles for interview reports -
First round interview about probability and playing game. Second round onsite was about 4 to 5 rounds. Each round with a different trader, interviews include probability questions, coding questions, betting game and variations and so on.