Pros
Amazon has quite a lot of smart people, and they're given free reign to solve problems the way they think best (after all, they have to deal with the aftermath). The result is a streamlined, low effort, build/deployment system, fairly low bar for building new services and tools, and the opportunity to try new things in a safe manner. the technical environment is top notch, and the important parts are implemented well enough (always some room to improve). Amazon is obsessed with metrics - when a service is deployed, part of the process is choosing metrics and monitors to ensure that any problems are caught automatically and fixed; due to the good tools, patches can be pushed out in hours, and rolled back in minutes, so responsiveness is expected. Senior management communicates fairly openly; the CEO fields questions at the quarterly meeting, and welcomes hostile or difficult questions, which surprised me. At a divisional level, I always had a good idea of where things were headed and the priorities.
Cons
Amazon will eat your life - pager rotation sucks, and if your service needs babysitting, you may not have an ops team to handle the general things. What this means is that a lousy service will take your free time and interrupt your sleep one week out of 6-8. This would be as expected for a lot of things, but some services are naturally chatty (external systems, upstreams that file a pageable ticket to find out why your service is acting up, etc.). In addition, the workload can be high if you find yourself in the wrong place - choose wisely. The downside of free reign with teams is that there is often little consistency of behavior, as each team implements what it needs; this can cause problems if you need something not offered. It also impacts crosscutting concerns - coordinating multiple teams is almost impossible. Payments is a high stress area, as is anything that supports warehouses. Having been in payments, it's getting better, but I didn't get along with one or two of the managers; I got a bit burnt out, then was denied vacation that I desperately needed and tossed on a deathmarch project., so that colors my views a bit Amazon has cheap benefits (frugality is the watchword, but it burns a bit when the most significant bennie is a bus pass). On the flip side, you are paid well if you do well.