Background : 14 years.
There were four rounds:

1. HLD :
   • Design a Cloud architecture for messaging, similar to WhatsApp.
   • Describe about a challenging change you did in a project.
2. LLD : Questions revolved around how you handled a challenging project, how you do code reviews, Sequence diagrams, REST APIs for a amazon package pickup/delivery application
3. Coding : Initial discussion around how you can catalogue a files on a HDD (for ex: B-Trees, SSTable, HashMaps etc.,), then about a interesting/tough project you have worked on. Given an array of integers, return an array with the index of the next greater element to the right (i.e with larger index). -1 if the element does not exist. ex: for 2 3 4 , we get 1 2 -1
4. Hiring Manager : Again behaviorial and how you overachieved something, how you mentored someone etc., Basically they try to evaluate based on "Amazon leadership principles" (this is public)

Closing comments: There was no telephonic interview. There was hardly anything coding/technical, almost 50% of the emphasis is on their leadership principles. Interviewers who took HLD, Coding rounds were good and patient. The interviewer who took LLD was very impatient and looked like he was interrupted from a debugging session and wanted to go back asap. He kept on repeating there is less time. Judgement based on how you demonstrated "Amazon leadership principles" in your previous projects can be very biased and people can simply come with ready made answers about some challenging situation. As per my friends who have worked there the technical quality of SDE2/SDE3 has come down, probably because of this weird interviewing questions? Glassdoor reviews of SDE3 paint a horrifying picture.