Former AWS engineer here.
I worked on a pretty critical product in AWS (big AWS service with lots of traffic) and I can safely say that it's totally up to your manager and pre-existing conditions which make up the job. My manager was great as a person but would always lack in my career-oriented goals (bigger projects, promotions, etc)
But what really sucked for me was the pre-existing conditions. Our on-call was pretty bad (40-60 tickets a week) and there was very little investment being put in to improve it. We had a lot of little scripts here and there which would solve extremely specific situations but no focus was ever put on in building a general framework or trying to reduce the ticket count. This often led to engineers taking the day off after their on-call due to the load and honestly it made people quite grumpy. And upper management was always much more interested in feature delivery since the focus was always on promotions and the more you delivered the better it looked for your manager. So now you have engineers with such a terrible on-call load along with pressure to deliver new features and projects within the atrocious tight deadlines that would be set. It was, to be blunt, a shit show.
Code quality was atrocious. We had one enormous Java method (>1000 lines) which would take care of nearly every single request coming into our service... With only about 7-8 unit tests. It was so difficult to get even basic things done to the point where any ticket that needed to be done would take a minimum of 4-5 days regardless of complexity. And of course managers and senior engineers would estimate small tickets to take around 1-2 days and then be shocked when 2 days later it's not even close to being finished. I will give Amazon credit that they do grill design reviews pretty harshly so those are done well in general. But code reviewers didn't care about quality or best practice. If it works then ship it.
I'm just not 100% sure about the whole PIP scene. Our service was extremely critical and we were extremely understaffed. So I don't think it applied to anyone in our org but I know of other teams who would have no issues in taking in a fresh college grad, making them do work for 6-12 months and then just randomly putting them on PIP. Sad but I've seen it happen a few times in my time there.
I'm glad I got the Amazon stamp on my resume and left. When I left, more than half my team and my manager quit around the same time too. It was definitely a wild experience.