Pros
I started at Amazon as an intern right out of university. I've found that there is a culture of learning and generally supportive coworkers/managers. There is a lot of work that needs to be done and many opportunities to make an impact, while this could be exhausting, the benefit is that you will rarely be left feeling like your job doesn't matter or that your just doing "busy work". Another pro is that there's a culture of candid feedback amongst management that helps you grow and learn, not wondering how you are doing.
Kontras
One of the cons of Amazon is that they are very frugal, this means projects that should have more staffing are typically running leaner than they should. While this benefits the customer because it ensures a scrutinized prioritization of work, it can lead to some overwork from the employees. The planning cycle has the effect of needing a lot data, projects, and documents to be delivered at one point in the year which can lead to some artificial stress induced by these dates. While the cycle is effective, there is a price paid for it.