A recruiter reached out initially with a link to online coding question (two questions : both fall in easy/medium leetcode)
After the online assessment, flew to Seattle for an onsite interview.
Amazon pays for your stay and flights. The onsite interview consists of 4 rounds. Be prepared to talk about Amazon leadership qualities that you have used in your life. The questions in itself were not at all difficult. The questions are intentionally vague. You MUST do some back-forths to get to problem statement and what should be the output, only then start working your logic. You SHOULD write code (real code) on white board.
You are covered if you read through CTCI. The questions once you break down to a simple problem with so-so inputs and the required outputs, you can easily (trust me on this) very easily come up with an algorithm. Know your graphs, trees, distributed systems, how to scale-up scale-out, threads (super basics of threads)
For design rounds, know your OOP and system design fundamentals.