I was referred by a friend who got a job recently at Amazon. There were two telephone interviews with coding sessions via an online shared editor (they see what you type). This was later followed by an invite to an onsite interview in Seattle. Stayed at the Hyatt over night and had a full day of interviews (5 devs, a dev manager and an HR lady). The office I interviewed at was nice. Didn't get to imbibe much work culture, though had lunch with the dev manager and it seemed nice enough.