I was initially approached through an employee reference. That was followed by an initial phone screening. A take home programming test was given. That test I expect is a test that changes based on what position you are applying for. Once the test was handed in, I was brought in for an on-site interview. The On-Site interview was a full day interview process. It was mostly made up of 1 hour sessions with 2 or more people in which they ask you about your qualifications and any questions that are relevant for them. These sessions included technical interview portions as well as "fit" portions to ensure that you fit the mold of the Blizzard culture. There was about a 1 week delay for each phase of the interview, after the initial phone screening.