I actually interviewed more than once for two separate TAM roles. The first round went through a series of 6 phone interviews. From what I understand I was final round but didn't get it. That started off with a technical interview which was a lot of questions surrounding the product stack. Be aware of new products and versions of vCloud, vSphere, vCAC, vCops, etc... Not sure if that many interviews is typical. The second time I applied was when they called me back after 5 months for another opening. This interview process took around a month and was a few more interviews technical, and scenario type questions. I'd suggest preparing notes with product info, as well as focusing on use case examples of your resume history.