The interview process started with a screening process which basically asked about my general background and stressed that the job would entail 80% travel or more on average.
The second interview was a technical interview ranging across all aspects of Microsoft Server tech, IP, DNS, etc. The test was difficult, and I didn't expect to get offered another interview afterwards. I later found out that it becomes progressively harder based on how you answer to truly gauge your technical level.
Finally, I was invited to a day long office interview. There were many other candidates there. You are expected to dress for success. You have to write an essay throughout the day in-between other activities, you have to perform a group exercise that later turns into a competition between the various small groups, and at the end each group is asked to have one teammate present their findings, giving a few people the chance to stand before the entire interviewing crowd and hiring staff and talk publicly.