Info on Focus/PIP
I've wanted to make an info post here for a while. Throw-away account, as the details of my time at Amazon are not public info. I was an L6 there for around two years, for reference. A lot of this info was on internal boards also (where I was active), before Amazon removed it (around the time the vocal people who were removed with the RTO push were removed/silenced).
As far as we could collectively tell (based on data gathered), at any time, around 40% of employees are on Focus. This is done to "prime the pump" for the required ~15% annual NRA targets: managers need to build a history for people to place on PIP, to meet the "stack ranking" style NRA targets. Important: You will almost certainly not be told if/when you are on Focus. I was on Focus for over a year, with no notification, no coaching, no extra/different communications from my manager, no extra targets or requirements, and no way to tell. I only discovered this when I was eventually moved onto a PIP. Many people will never know if they are on Focus.
Managers have ~15% annual PIP targets, via the stack ranking program. Being placed in PIP is primarily a necessary bookkeeping step to fire someone. Somewhere around 5% (WAG) of employees "survive" a PIP, but it's designed to fire you, so you will not get support from your manager (he/she has already decided to let you go at that point). You'll only survive if you have a higher-level manager override, and move you to another group.
Important: The goals for the PIP will almost always be absurd, vague, and unattainable. This is very different than the internal messaging, where they will try to gaslight you by saying they are objective and achievable; they will not be. This is something I explicitly asked my manager about, when my PIP plan was basically "do the equivalent to what the team has spent 6 months working on in 4 weeks, and we'll tell you if it's good enough". The process will not be fair, objective, or remotely possible, and is designed to ensure you will always fail. See the above point about the only way to "survive" is to have a higher level manager save and move you.
Also, for clarity: if you are placed on PIP, unless you are saved by another manager, you will never work at Amazon again. This is also by design: the org knows you will be disillusioned at that point. It's also not the end of the world: Amazon is one of the worst employers out there, aside from compensation, and given options you probably shouldn't want to work there more than once anyway.
Amazon, as an org, does not care about their employees or objective data (they claim they do, but they do not). This became transparently evident during the initial RTO push, when all the data in the world didn't move the needle for anything upper management was mandating. This may have been true under Bezos (I cannot comment, wasn't there), but it's not remotely true under Jassy. Currently, profits and stock price are prioritized over everything.
Anyway, I hope the above helps someone. Despite my experience, I think I got positive value from my time there; Amazon still looks okay on a resume, I have great references from elsewhere, I learned stuff and did some good work while I was there, and there's residual value in the compensation expectation. Amazon is the worst company I've ever worked for (in terms of how they treat employees), and I'm in a much better place now, but I wouldn't necessarily tell people not to take a job there, as long as you know exactly what you plan to use them for (as they will certainly be using you mercilessly and without any regard for your welfare).