Applied as a trading, development, or research intern. I went through 3 phone interviews before I was finally called to do an on-site interview at New York. HR made the process of traveling to New York from California fairly painless, and I opted to fly in the day before my interview to get some rest. On-site interview was composed of four separate interviews, in addition to lunch with a current employee and a session afterwards to talk about the internship in general (after I received my offer). I interviewed twice with traders, once with the devs, and once with research, as it was yet undetermined which type of intern I would be. All of the interviews were fairly tricky and required some thought - in my first interview I competed with another candidate to win trading contracts, which was stressful - but most of the questions were pretty fun as well.