Amazon Interview Experience | On-Campus 2021

Screening Round: The screening round for amazon has a variety of questions:

1. Debugging questions:  Very very easy, you don’t need to prepare for this
2. Coding questions: There was a total of 3 questions, 1 easy and 2 medium-level questions. I don’t remember the questions.
3. Work style assessments: It’s basically an MCQ to assess your behavior and your attitude
4. Aptitude questions: Prepare from GeeksForGeeks

Round 1: The interviewer was SDE1 and he was friendly. He introduced himself and asked me to introduce myself. After the introduction, we jumped right into coding questions. He asked 2 questions:

1. https://www.geeksforgeeks.org/problems/rotten-oranges2536/1. Initially, I couldn’t recognize the problem as Multisource BFS, he gave some hints, then I applied  Multisource BFS to solve it. He made me write the code.
2. https://www.geeksforgeeks.org/problems/special-stack/1. I had seen this question before. So I easily solved it. I had to write full code. He seemed satisfied with my code.

Then he asked me if I had any questions for him. Use this opportunity to convey that you are really interested in the company. I had prepared for this question the previous night. So I asked questions like: “how’s workload at amazon”, “how long does it take for SDE1 to get promoted to SDE2”, “in which office do you work”, “how was your experience in the initial days when you joined amazon”. The interview went well. I had managed to establish a connection with the interviewer in that 1 hour of discussion. I knew I will get selected for Round 2.

Round 2: In round 2 there were two people both SDE1s. The round started like any typical interview; the interviewers introduced themselves and asked me to introduce myself. Then they asked a behavioral question: “If you want to choose between best-solution (but infeasible-solution) and substandard-solution (but feasible-solution) which one would you choose. Give supporting evidence by narrating an event in your life where you had to make such a decision”

Then we started with programming questions

1. https://www.geeksforgeeks.org/place-k-elements-such-that-minimum-distance-is-maximized/. I discussed the approach first. They seemed convinced with the approach so they asked me to code it up. After coding it up, they even made me walk through the code using an example. They were satisfied.
2. “Given a random array what algorithm would you use to sort it?” I said, “there are several sorting algorithms to sort a random list, each has its own pros and cons. We have to choose the right algorithm for the given situation”. Then he asked me the time complexity of some popular sorting algorithms. Then they asked, “which sorting algorithm would you use if all the numbers in the array are in the range [0,100]”. The answer is counting sort.

After these two questions, the interview was officially over. They asked me if I had any questions for them. I asked questions like: “How’s workload at amazon”,  “If you are not familiar with the technology which is being used in the projects allotted to your team, how do you go about dealing with it”, “Did you notice any flaws in the way I communicated my ideas while solving coding question ”. We had a great discussion. They were very happy with me. I knew I will get selected for Round 3.

Round 3: This time, the interviewer was a senior software engineer (SDE3). He was very cool. He was actually in Bermuda shorts when he was taking my interview LOL. I felt his conversation was more engaging than the other interviewers’ from the other rounds. No wonder he is an SDE3.  

• The interview started with a casual conversation. He told me about his history, and the team he works for at Amazon, etc. We spent some good 15 minutes talking casually. I could tell that he is enjoying talking to me. Then the actual interview started. He said he is going to assess my behavior and problem-solving abilities. He allowed me to choose whether I wanted behavioral questions or coding questions first. 
• I was having an engaging conversation with him and I didn’t want to break the streak. So I said, “I would like to have behavioral questions first”. Then he asked some standard questions listed here https://www.amazon.jobs/en/landing_pages/in-person-interview
• Then he asked a coding question: “Given an html-document check if the hierarchy of tags is valid or not”. I started off with the idea of the stack. But he hinted that Tree could be a better data structure for this. Then I represented the hierarchy of tags in the form of a tree and I explained to him how I might go about solving it.  I hadn’t solved similar problems before, so I was basically exploring how I could solve them. I wasn’t sure how to solve it. I couldn’t solve it completely. I was just beating around the bush. After some time the time was up so he interrupted me. I  was totally unsatisfied with how I solved the problem. I thought I had made a negative impact. I was doubtful about getting selected. But I guess my answers to behavioral questions saved me. 

VERDICT: SELECTED