Pros
The reputation that you get for being a Software Developer at Amazon, means you are above a certain bar. If you work on backend services, you will be exposed to all things AWS.
Kontras
If you are lucky you get to work on a good team with good management, I know some people that are in that situation. However, my experience was on the other side of the coin, small team with tier 1 services and terrible manager and skip level. There are some really bad managers that will make your time at Amazon a nightmare, some are former developers that are new to management that will not stick for the team member, you will be overloaded and will work crazy hours and no matter whether you complain on the different survey mechanism these managers will just be shuffled.