Phone screen. HR sent a detailed preparation email which explained how I could be asked about Amazon leadership principles, and said I should be familiar with the content of the AWS blog. It also included a link to a shared coding whiteboard. Per the HR suggestions, I prepared by developing notes from my background of how I had applied the various leadership principles, by researching current AWS issues from the blog and other sources, and quite a bit of time dusting off my coding skills in various languages.
The interviewer (hiring manager) did not call in as scheduled, but sent a substitute instead who phoned in 10 minutes late. The substitute hadn't had time to prepare, or perhaps even read my resume ahead of time, and did not ask any questions related to what the HR email described. He asked generic questions about my background, including my toughest challenges, and proudest achievements. He asked only one direct question toward the end which seemed unrelated both to anything I had done and to the role we were screening for (see below).
I thought the screen went well, but didn't get a good read, so was happy when the HR person contacted me a few days later for a second screen with he Hiring Manager (who was supposed to have conducted the first screen). Perhaps not learning my lesson, I prepared similarly for the second screen, but again nobody phoned me at the appointed time or for the 30 minutes I waited. 45 minutes later, in response to my various emails and phone messages, a different HR rep called me to say "I'm sorry but the Hiring Manager changed his mind and no longer wants to conduct a second phone screen."
Please. Hire me or not -- that's your call -- just don't waste my time.