Citadel Securities Quantitative Researcher interview experience

The focus was on a mathematical proof problem, and the interviewer didn’t offer much guidance when I got stuck, which made the experience feel more isolating than it might have otherwise.

Aside from that, the rest of the interaction was pretty standard—enough structure to know what was being evaluated, but not much scaffolding once I lost my footing on the proof.

I received a rejection within about a week. What stood out to me was how much the outcome depended on keeping momentum through an open-ended proof rather than relying on hints.