Disclosure, long time principal at AWS but all statements are my own opinion. 1. Yes, but I believe its more culture than bureaucracy. 2. open transfers 30 days post hire, IIRC. 3. More org than team, and exceptions abound. 4. Yes. 5. Not quite; unregretted is employees with low perf rating leaving there is also regretted attrition which is mid-high perf rating employees leaving. The total is inline with industry norms (10-13%/yr) in my experience.