Avantages
Other companies think AWS's products are cool and innovative. Thus they assume AWS engineers must be high-quality, which facilitates the job search :).
Inconvénients
People are treated very poorly -- I don't think they are even trying to compete with other top tech companies for engineers. My team inherited too much technical debt and brittle legacy systems that had been neglected for years despite causing increasingly serious problems as the business scaled. We spent all our time remediating customer issues but never building anything new or even properly maintaining our broken software. The on-call, status reporting, deployment processes, etc., were brutal as well. Overall, every aspect of working here was draining and I left as soon as I could. Fortunately I discovered that being an engineer outside of Amazon isn't so painful :).