First an initial phone screen. Then I was asked to come in for an in person interview. Usually that's it, but I was in a pool of three other candidates vying for the job. Because of this, I had an additional phone interview. The most important part of the interview was the in person. Viacom is all about culture. If your previous work experience can show you can do the job, then you are good to go as long as you fit in culturally.