I had one phone interview with the hiring manager that lasted about an hour. It was very low key, and simply consisted of questions about my background and interest in the company, as well as an explanation of the company and the role. The next day I was contacted and told that I was to be flown to Wilmington for a day of interviews a few weeks later. That day consisted of meeting the hiring manager and touring the office, then four or five ~40 minute interviews, each with 2-3 people of varying levels of experience. In between, I was taken to lunch with some of the younger analysts. The interviews consisted of mostly personality and fit questions, but in each one there were a few brain teasers, similar to the ones listed below. It was important to talk through these problems so your interviewers could get a sense for how you solved problems, and it didn't matter if you figured out every single one (I know I missed a few).