Two technical phone interviews - 1. Covered general CS concepts and previous projects 2. Coding using collabedit, two questions that took about 45 minutes. Both interviews were challenging and pleasant experience for me. I was then flown onsite to Pittsburgh for a round of technical interviews. I signed an NDA, so cannot discuss the specifics. Broadly, OS concepts, distributed systems with some networking, Datastructures & Algos with a lot of white board coding. All the interviewers were very professional and pleasant. I enjoyed working through the questions and coming up with workable solutions on the white board.