Pros
Amazon is a company full of talented people. Engineers are onboarded to Amazon's culture of drive, ownership, and clear communication and direction early on. You'll find that some teams work like a well oiled machine while most operate like a scrappy startup with a very high bar. There's also a lot of change here, so it's a great fit for someone who is adaptable and prepared to make smart career choices ahead of the curve. Be receptive to mentors who provide constructive feedback and wary of those who perpetuate ambiguity or only tell you what you want to hear. Be your own best advocate and back it up with data. Amazon is an amazing place for curious individuals. People who work in completely different countries and areas than you are more than happy to have a quick sync to satisfy your curiosity about what the company is doing in other areas or provide career advice. Mentors are often happy to provide support past your employment directly under them and your network is likely to expand into a wide subset of the industry over time. Engineers are encouraged to pursue their interests and are supported in career changes even if they are unconventional or are not beneficial to your direct management.
Cons
Be aware that Amazon is a very competitive workplace. Be intentional about ensuring your managers play a proactive role in your development and that your team has business need and clarity without too much thrashing. If your team doesn't show dependable signs of being able to develop and promote you, find a new one quickly. Some teams have very poor work life balance. Build trust in your ability to deliver and be clear and liberal with the boundaries around your personal life. I've been on teams where the manager asks developers to bring their laptop on vacation and others where that would be discouraged. Good leaders will support you in making your day-to-day work best with your life so you can excel in both.