Status: CS Master, 2 YOE
Position: Front End Engineer L4
Location: Virtual
Date: March, 2019

1st Round (1 hour):
100% Behavior

2nd Round (1 hour):
20% Behavior
80% Technical -- matrix, provided two solutions BFS and DFS

1 Hour Break

3nd Round (1 hour):
20% Behavior
80% Technical -- HTML，CSS, JS. Basic layout styling, mainly focus on update page content based on JSON provided

4nd Round (1 hour):
100% Behavior

I had very good interview experience with Amazon. HRs are helpful and interviewers are very nice people.
Did 50 Leetcode problems mainly cover array, bst, and matrix.
https://javascript.info/ this is a very good resource to learn the topics that you are not familar with.
Prepared 11 working experience stories. Still not enough. Needed to think about new ones during the interview.
Better questions to ask interviewers will be very helpful. At the end of each round, you will be asked to ask questions.
I am lucky that no system design questions were asked (I saw other posts says they were asked design questions). Prepared 10 questions, not enough.
My interview went through very well. Had very good conversations with the interviewer. Recieved offer on the fifth day after my interview.

GOOD LUCK to Everyone!