My gut has always told me not to apply here but I was curious but I thought I'd "Learn and Be Curious" ;)
Email communication from internal recruiters was very poor. My first call was completely informal but I was told to prepare for leadership questions etc (which takes hours). They use preformatted messages that aren't specific to your process.
Just days before my all day loop interview I was made aware of extra requirements and also told no feedback was not allowed to be given, in the event of not being offered. I wouldn't have bothered applying as that's just sheer arrogance.
Think VERY carefully before applying. Their process requires you to invest days of your time (interview prep, technical test, presentation and 5 1 hour interviews), when in reality they could find out if you meet their "bar" in a 1 hour coding session.
Half way through I was uncovering more about Amazon that made me feel it's really not a great place to work anyway. I would have only accepted a very good offer. It's very clear they are looking for workaholics who are used to working with very difficult people on a daily basis.