First interview was a phone screening with a few qualitative questions (i.e. tell me about yourself, why do you want this job, why do you like Citi, etc.). Second interview was a full super day at headquarters, consisting of 5 back-to-back 30-minute interviews. Questions weren't too technical, but getting very similar qualitative questions over and over again was quite tiring. Overall, a good experience and not too stressful.