Amazon SDE-2 all rounds interview experience [REJECT]

Round 0 (Online Assesment)

Two questions on a hackerrank test:

1. An easy/medium level treeMap question. Fully solved.
2. A medium/hard question, in which my 60% test cases passed.

Round 1 (DSA)

First 30 minutes on Leadership principles.
A string pattern matching, similar to this leetcode Hard problem.
https://leetcode.com/problems/longest-happy-prefix/description

I gave two approaches, though both weren't the most optimal. The interviewer didn't give any hints. Just asked clarifying questions regarding my code. I had to write running code for this.

Round 2 (LLD)

Design a Restaurant Booking System.
He wanted to know the classes/entities (Table, Booking etc), APIs and database schema.

The interviewer was helpful and provided hints. I had to used Amazon's internal tool called Bluescape for this, instead of excalidraw. Login to Bluescape beforehand, to save issues during interview.

Round 3 (Hiring Manager/HLD)

Design Amazon shopping cart. The focus was handling inventory for multiple booking buying things at same time.

The interviewer wanted a perfect answer directly, instead of iterating and reaching on a solution. So, the first solution must be the perfect one. I bombed the interview big time.

Round 4 (Bar Raiser/ Problem Solving)

In a social group of n people labeled from 0 to n - 1,friendships are being formed over time.
You are given an array logs, where each log entry logs[i] = [timestamp_i, x_i, y_i]
represents that persons x_i and y_i will become friends at time timestamp_i. Each friendship is transitive.
For millions of such datapoint, find the earliest timestamp, at which all people become friends.

I gave a LinkedList/Set with Map approach. But this question would be solved by Disjoint set, and got the rejection.

Best part of the Amazon Loop was that I got detailed feedback after each of my rounds, which helped with my preparations. Most companies don't do that.

Note: In all the above rounds, first 30 minutes were dedicated to Leadership Principles, typically two questions and several followups. So, you'd have only 25/30 minutes for technical stuff, so giving a brute force approach isn't the best way. Go with the most optimal approach as your answer, if you know it.