Pros
It feels like there are lots of different startups under one big company, so in daily work you have lot's of flexibility, but at the same time you have benefits of big company. Different teams tries to help each other and you can ask for help almost anyone. This couldn't work without same ideology - and in Amazon ideology build on "Amazon Leadership Principles" which unites all. Company gives a lot of effort to help you with almost anything, and speaking of most customer-centric company - employees is also customers, in some way.
Kontras
Not every piece of Amazon is flexible. In hiring process there are lot's of bureaucracy, but they REALLY try to help you with anything. The whole process of hiring with relocation took me 6 month and this is fast one.