The first interview was on campus, 45 minutes. They asked me basic personality questions (who is my role model, what do I look for in a friend, what am I most proud of) and then when I mentioned stats they asked me 2 very simple stats questions (what does R-squared mean, what does a positive slope in a regression mean). After that I heard back almost 2 months later. The next round was 2, 45 minute, online interviews, also only personality based questions. Honestly the whole process was very friendly and relaxed, but also a little vague. I'm not sure what they base their decisions on. Make sure you know your resume very well and be prepared to talk about things in a "STAR" method. Situation, task, action, results. Then if they have questions elaborate on the details.