When I interviewed, the instructions I was given by the recruiter were very explicit. For the Leadership Principles, I did my hardest to come up with at least two items for each LP, and of course they had to be in STAR format -- Situation, Task, Action, Result. To that, I added a URL to back up my story for all of the cases where I could.
So, when I used the example of designing and starting to build the replacement e-mail system for ASML for literally zero additional cost [0], I pointed them at the URL for the Invited Talk that I gave based on that work. And when I used the example of when I broke all e-mail across the entire Internet, I pointed them at the URL for the article that was published in The Register. When I talked about what I had learned about Chef and DevOps, I pointed them at the invited talk I gave in Edinburgh entitled "From zero to cloud in 90 days" and the accompanying tutorial I taught called "Just enough Ruby for Chef". And so on.
I really feel that having the URLs to backstop my stories helped me sail through that part of the interview.
In my case, I wasn't being hired as an SDE, so there wasn't much programming tests they wanted me to take -- one of their senior developers did connect me to a shared coding platform, which we really just used as a shared whiteboard. He asked me some questions on how I would solve some problems, and I used my 30+ years of experience with Bourne shell and bash to show him stupid first order solutions to those problems and then we talked about what some of the second and third order solutions might be.
The longer I work at AWS, the more convinced I am that everything depends on the people you're working with. There are good teams and bad teams. There are good managers and bad managers. And if you can find a good team with good managers, then you're golden.
In this respect, I don't think AWS is materially different from any other employer I've known.
[0] They had already bought all the hardware, including some stuff I scavenged from a closet where they had been sitting new-in-the-box for a couple of years; the OS was covered under their site license; all the application software was open source; and my time was free because I was already there under another contract)