Amazon Interview Experience for Software Development Engineer (On-Campus) Internship 6 Months

Hi, I am a Final year student pursuing my B.Tech in Information Technology from VIT Vellore.

Amazon visited our campus on 20th July 2022 for hiring SDE interns.

First round: The first round was a general Online assessment. Before the online test, our college had sent a shortlist of students who could register for the said job title on the Amazon Jobs site. Only those shortlisted students got the OA link. The OA was conducted on Hackerrank and had a test window from 9:00 AM to 6:00 PM. The test was a basic test consisting of 2 DSA-based questions. The questions were shuffled for students in different combinations. Around 4000 students gave the test out of which 440 students were shortlisted for the Interview Round.

Interview Round(1 hr 45 mins): Started with the interviewer’s Intro and then mine. The interviewer was pretty chill and friendly and he explained to me what was his role in Amazon and what team he works for. 

Later he posed me 2 questions:

• The First question was on Linked List: “Suppose you have 2 numbers stored in 2 Linked Lists, add the numbers and store their result in a new linked list.” This was the question, this is a pretty basic question and the interviewer wanted to see if I knew the basics. People who could not answer the basic questions were rejected on the spot.

https://www.geeksforgeeks.org/add-two-numbers-represented-by-linked-lists/

The approach I used: Iterate through both lists to the end and append the leading zeros of the lists with a small number. Then call the recursive function on the starting node of both lists. The recursive function calls itself on the next node in both lists until it reaches the end. This function creates a node for the sum of the current digits and returns the carry.

Steps to reach the solution.

• Iterate over the two linked lists and add leading zeros in case one list has fewer digits than the other.
• Start at the top node of both lists and call the recursive function on the next node. 
• Continue to the end of the list.
• Creates a node for the sum of the current number of digits and returns the carry.

Then the interviewer asked me if I was comfortable with graphs, which I was not so he asked me a very common question about trees. 

• The Second question was a variation of https://www.geeksforgeeks.org/minimum-time-to-burn-a-tree-starting-from-a-leaf-node/

I was able to solve the question with a few hints from the interviewer and then he asked me about the time complexity of my solution. I took some time and gave him the answer. 

After these two questions, he asked me if I had any questions for him, to which I asked for general feedback on my performance. The interviewer told me that the interview went pretty well just that I should be confident with all the data structures and especially the advanced ones because they are used in their daily life. At this point, I regretted that I did not study graphs and I knew I would not be selected.

This was the only round of selection and then the list of selected students was released.

Verdict: Not Selected.