Amazon Interview Experience for SDE-1 (Off-Campus)

In the month of April – May Hackathon named HackOn was held on the HackerEarth platform by Amazon.

Round 1: Coding Round

Time: 3 questions in 2 hours

• Given a string of 0’s and 1’s. You are allowed to do 2 operations on this string.
• Exor of any 2 consecutive elements and replace them with the result.
• And of any 2 consecutive elements and replace them with the result.
• Our question was to return “Yes” or “No”. If we can reach 1 after n-1 operations on the string. (Hint-Just check if one is present in the input string)
• Range sum question: https://www.geeksforgeeks.org/problems/sum-of-query-ii5310/1
• I don’t remember but was Leetcode Easy.

Our Idea was not selected but I got a mail-in July regarding the further Interview process. The criteria for selection was all 3 questions must be solved in 1st round.

Round 2: Interview Round 1

This interview was taken by an SDE-1 and was very friendly. Two questions were asked I was able to solve both in 1 hr.

• https://www.geeksforgeeks.org/maximize-partitions-such-that-no-two-substrings-have-any-common-character/
• A simple priority_queue question. Multiply 2 numbers and put them back in priority_queue and the answer will be the last standing number in priority_queue.
• Analyzing time complexity was an important part of the interview.

Note: Study heap in detail.

Round 3: Interview Round 2

This interview was taken by an SDE-1 and was very friendly. One question was asked I was able to solve it in 45 minutes.

• This was a variation of the Job Scheduling problem. The task was to compute the time needed to execute all queries. ith query denoted Jobs that arrive at the time i. There can be multiple jobs entering at a time. Our processer can do n jobs at once.

Queries - [[1, 4], [3], [], [3, 1, 2]]
Query slot - n (eg 2)

• The problem was then modified with priorities for jobs.
• One question based on Amazon principles was asked. Tell me about one of your learning experiences. (I told him about my internship experience)

Round 3: Interview Round 3

This interview was taken by a senior developer with more than 4.5 years of experience at Amazon. He was very friendly and really tried to understand my approach.

• We had a casual discussion at the start followed by a depth discussion about my internship. (15 min approx)
• https://www.geeksforgeeks.org/recursively-reversing-a-linked-list-a-simple-implementation/
• https://www.geeksforgeeks.org/add-two-numbers-represented-by-linked-lists/
• I told him we can reverse a linked list using pointer manipulation, but he said he wanted a different approach so I had to try and write recursive implementation on spot. These 2 questions took me 30 minutes
• https://www.geeksforgeeks.org/problems/detect-cycle-in-a-directed-graph/1

The interview was over in 1.5 hr.

Verdict – Selected

Note :

• Ask good questions to the interviewer. Asking questions is not about you know more about the company, it’s about the interviewer replying and enjoying talking to you. Ask regarding what he does in day-to-day like (In work from home office). Or something related to his current project. The hiring process in Amazon is quite slow it takes time, Took me 1 month for 3 interviews and 4 months from giving tests to getting selected.
• I gave more than 15 interviews and so many tests (GS, Amazon, Linkedin…) Was rejected in all. Didn’t even get an internship in any reputed firm. (PS: I interned in a small Pune-based startup).

Keep working hard and all the best.