I was referred by a friend from college who worked in the New York office. I applied for Chicago office position. The whole process lasted about 2-3 weeks, including an initial phone interview and an in-person interview. The initial interview was pretty standard. They take a lot of interest in the research experience you have and ask questions about research methods. In-person interview consisted of short interviews with 3-4 people, a case study of sorts, and ends with the opportunity to briefly shadow someone in your position currently. Ended up getting a job offer but took a different one that paid for my move to Chicago. Seemed like very long hours. Takes a while for upward mobility in the company.