I applied online. The process took 2 months. I interviewed at T-Mobile (Bellevue, WA) in Feb 2018
Interview
The interview process consists of five rounds of phone/skype interviews with directors and VPs, followed by day-long in-person interview with c-suite. You must be recommended to move forward by the interviewer in each round.
Interview questions [1]
Question 1
Questions primarily centered on leadership and management, including typical situational and "tell me about a time..." questions. They are looking for substantial experience leading large teams, especially in an environment where your employees are lower-level (e.g., call centers).