Not sure what team you were on, but in my time at Amazon I never saw a company whose teams were more in-sync in terms of process, tools, frameworks, languages, etc. Say what you will about the work environment, but it's saying something that with the churn you mention (which is real), they are still able to deliver consistently. It's a well-oiled machine.
I worked for AWS. I wont say much more. The average employee churn stats speak for themselves. Amazon burns folks out. Uses them up. Not like the valley at all. Leadership principles [1] door desks, bezos cult.
