Avantages
It's good to be the king. AWS is the market leader, but engineering doesn't act like it. Extremely innovative and fast paced. If you appreciate the technology it never gets boring to sell it. The people are amazing, and because the hiring process is so daunting odds are most of your peers are solid contributors. Great opportunity to make money if you are hungry and resourceful.
Inconvénients
There are many layers of middle management that came from far less innovative companies and it shows in the increasing amounts of bureaucracy and politics. The hiring process is arduous and sometimes freezes out good candidates. Upward mobility is really hard, especially with many layers of middle management almost all of which were hired externally.