Citadel Quantitative Trader interview questions

It was a 45-minite Phone interview. We started with background introduction, basically going through resume, and then we did a coding problem. Finally there's a questioning time for me to ask any question about the company.

I was invited to a university networking event in July, talked to the recruiter and a few traders there, and got an on-site two days later. It was 3-4 back to back interviews with traders on different teams.