It was a phone interview with 3 Sr. Managers. I went through highlighted projects in my resume and they asked a lot of follow-up questions. Most were behavior questions. Afterwards, they also introduced what they were doing at T-Mobile.

Entire interview process conducted over the phone. Called initially by someone in HR who went over basic resume qualifications. Called next by hiring manager about 1 week later and had 1 hour interview. Called 1 week later for two back-to-back 1 hour interviews with my hiring manager's direct supervisors. Hiring manager interview was the most challenging, as the questions were more case-driven; secondary interviews were more behavioral as well as testing level of interest and knowledge about the industry. Interest in the industry (or at least in tech) was more important than knowledge, but having some understanding of the telecom industry will help a lot.