Amazon Software Development Engineer interview questions

The HR person contacted me on linkedin and then called me to talk about experience, salary, relocation and basically tell me how great Amazon is as a place to work. The phone screen consisted of an introduction and two questions. The first, a simple question about binary trees. The second a live coding session where the interviewer watched me as I typed code for a more complex string algorithm. I was then asked about the time complexity and also to improve the time complexity by further optimizing and re-coding my algorithm. It last 45 minutes total. I was given positive feedback the next day via email. I was given flights at my convenience, a super nice hotel, and $80/day to use on taxis to navigate Seattle. The on-site interview consisted of 5 rounds. The first an OOP design on the whiteboard and then further extrapolating the design as complexities were added. The second a fairly simple binary tree algorithm question on the whiteboard with time complexity analyzed. The third lunch with the manager talking about my past experience and leadership principles. The fourth (bar-raiser) a more complex binary tree algorithm question on the whiteboard that required the use of other data structures (hashtable) to further optimize it. The fifth a discussion about software testing and bug-fixing. I was given positive feedback that same day 2 hours after interview.