There were two rounds, an on-campus interview and a full-day interview at Microsoft in Seattle. The first interview was really simple, it was 30 minutes and there was just one easy whiteboard question. The second round was really good, they did a great job of setting up all the logistics (e.g. flight, reimbursements). I interviewed with five people, and they were all very friendly. I was asked some whiteboard questions with each person, and they were almost all linked list questions for me. For Microsoft's interview process, I recommend CTCI and LeetCode for the technical interview prep. Make sure you also research the company a bit and get a feel for the vision/culture, this will help a lot for the behavioural questions!