Location : Seattle
OA : https://leetcode.com/problems/robot-bounded-in-circle/ but instead of String the directions were in a List.
Onsite:

1. Sum of all binarysearchtrees in a tree. So, basically the interviewer wanted to create a tree and then if there was a BST, add the value of all the nodes in the tree.
2. OOP/Coding : Design a game where there are multiple players, you can either add a new player, update their score or display Leadership Board
3. System Design : Design Twitter
4. Given a directory, create a method like FIND where you need to find all the files under that directory. Directory can have other directories, so you need to check and retrieve all the files.(https://leetcode.com/discuss/interview-question/369272/Amazon-or-Onsite-or-Linux-Find-Command)