Pros
Your experience at Amazon is largely team-dependent. I've been on teams where I've had a great experience, with a project that had considerable buy-in. Other teams end up having many issues, with projects being abandoned or redundant. The people at Amazon are smart, and very hard working. The work culture I would say isn't as awful as you would have expected a few years ago, and there's been a lot of effort to improve that area. The people are not the problem, it's the corporate structure and the priorities higher-up.
Cons
Abysmal HR structure. I had to communicate some urgent matters a few months before my start-date, but it took several emails to multiple people. Turnover rate is also high-- in between my internship and my full time return offer, I had changed between five different recruiters. Disturbing lack of concern for ethics. AWS powers ICE technology. If you try to speak out, they will put you on a dev plan-- a polite way to threaten you into quiet. Rekognition is a facial recognition technology which they're trying to implement for the government, which could be used to police immigrants and citizens. Ring is a home-security technology that has been discovered to have partnered with 200 law enforcement agencies (with racial profiling issues). There have been "business dinners" between Amazon execs and government officials. There is no sense of accountability when developing technology used by the government, not even a basic standard of ethical guidelines. Employees that bring up these issues in various letters, protests, and articles have been met with complete silence. Their approach is simply to ignore. Manager-dependent career trajectory. There are some good managers, and some... not so great. Politics are huge, as in most large corporate tech companies. Stocks are on an awful vesting schedule, rewarding you for staying as long as possible instead of incentivizing you to stay of your own accord. People leave Amazon very quickly and within my team there's been at least three people who have left or switched teams within this year. Please avoid working for Amazon if possible. It will wear down your soul.