Pros
Lots of smart and dedicated people, gym on site, beautiful campus, competitive pay, challenging work (not a dull moment) and an opportunity to learn something new nearly every day.
Cons
Top-heavy, incompetent and self-servicing managers are allowed to run areas they have zero background in that makes them insecure, so they lead by fear, eliminate strong subject matter experts who can jeopardize their careers and the whole gravy train arrangement by exposing incompetence and real issues management is not capable of fixing. To secure their position they internally hire clueless employees who will never get hired for the same type of work outside of Amgen, reward them, so they feel forever obliged and provide the most rosy and fabulous feedback to the next level management in the skip-level meetings. Highly bureaucratized processes, tons of questionable and wasteful activities that likely provide job security to those who implemented them, but are extremely painful for others.