Pros
If you are in the right group then it could work for you. Lots of impactful work to be done. You are free to do whatever you want. You can learn a lot. All folks hired are bright. There are no non-performers.
Kontras
Unfortunately some groups are very unethical and can throw off researchers also. Here few managers try to hold you to do what they want and can stress you to point where you move into another group within amazon or leave amazon. The HRs are useless and will only use your own information against you. So if you get the right manager long time workers told me that they stick on or else leave within a years time. My own co-workers motivated me to move on and quit. Lots of them quit as well. The bad manager was left with hardly few employees. Managers also subtly make you work even on vacation. Benefits are poor compared to other FAANG which is well known.