First contacted by college recruiter. Then had on campus interview with that covered my resume and some technical questions. In few days, I was invited to Redmond. Provdied all utilties, hotel, and flight arrangements. At on-site interview, met with 4 different interviews. Basically same format: resume+general questions and technical questions. One of the question was, given an array of integers and sum, see whether there is a combination that adds up to the sum. I answered all technical questions for the first two interview, but lost focus after lunch. You better prepare for a long day. Especially last interview seems to be the deciding one.