Pros
T Mobile is a place with so little structure and governance, it's really up to you as an employee to seize any opportunity. A strong performer can create a position here. IT is very central to business success, and largely recognized as a player in the outcome. It's a fun culture, with great people, good pay, and nice location. T Mobile has a very entrepenurial spirit and innovative products... They keep secrets so well, that they forget to tell customers about the product...
Cons
Executive leadership has largely been incompetent for the last 7or 8 years... The cross department politics and inconsistecies have crippled the company and force disfunction. T Mobile solves business problems by throwing bodies at the situation, creating unsustainable process. Leadership decisions are driven by hunch and gut assumption (and manufactured data), rather than measurable metrics. The recent shift to German leadership appears to have only been for show and positioning T Mobile for purchase. It really runs as 5 separate companies with conflicting priorities and poor communication.