Interview with the hiring manager and the team of analysts. It was a challenging process, yet they provided great insight. Overall the manager wants to understand the candidate's approach to solving a complex problem. It is less important in the interview to have the right answer, and more important to fully explain how you go about tackling a difficult data analysis task. Also, it is important to do at least some research on the SmartTrack tool prior to the interview as well as the company as a whole. This is a great company with great people, so the difficult interview is definitely worth it.