AWS has a lot of things I don't love (not least of all, their policy towards developing games in your spare time), but they had a ton of rigor around setting goals while still giving dev teams the opportunity to (mostly?) drive the details of what those goals were. (I've heard this is maybe not the case in all AWS teams, but I had some great local leadership as well.)
If they could fix a couple of deeply set cultural issues (open source and side projects were definitely hard or impossible), not lean quite so heavily on their employees (I was oncall 24/7 for months in the worst times and received no extra comp), and disconnect themselves from whatever is going on with the retail side's treatment of labor.... Well, I'm not sure I'd come back, actually. They'd have to change quite a bit more -- the promo process, the stack ranking/"top grading" twice yearly, better benefits and comp...
But I do genuinely miss working in the AWS org. There's a lot of incredible things to learn there. While I don't see myself coming back, the lessons I learned there have been absolutely invaluable.