Pros
Amazon is an astonishing place to work. Highly meritocratic, with enormous weight given to KPIs and metrics, and letting data guide your way. The high hiring bar means that you'll genuinely be working with the smartest people around - I spent the first year trying not to be the dumbest guy in the room. The green field thinking is awesome - you can approach problems without constraints. The leadership principles are also superb - they work, because Amazon uses them to guide and steer every part of the company, from hiring, to making strategic decisions, to resolving point issues - that makes them very, very powerful as a way to align an entire company. I also got to work with some of the best SVP/management talent in the world.
Cons
Jeff Bezos - "You work smart, hard and long - and two out of three don't cut it. " The working hours can be appalling - I was doing 73-74 hours per week, and it's very unsympathetic towards anything outside work, like family. It's also quite an unsentimental business - people don't tend to build great personal relationships, or if they do, they can be jettisoned quite fast.