Amazon Wow Interview Experience for SDE Internship 2022

I applied for Amazon WOW SDE internship in June 2022. (for 2023 passouts) There was a total of 2 online coding rounds, and 1 technical interview.

Online Round 1: (July 2022): Platform: Mettl. It was 90 mins – 40 MCQs (5 questions from each topic – OS, DBMS, pseudo code, Linux, Software engineering, Software Testing,..) and 1 coding question.

Online Round 2: (August 2022): Platform: Hackerrank

I received mail that I have cleared the first online round and the next step is to register on the Amazon jobs website. Then link to 2nd online round will be given there. This round has 2 coding questions for 45 mins. 

Technical Interview: (September 2022.)

• There was only 1 round and I attended it in the Amazon office.
• The interview lasted for around 1 hour and I need to solve 2 coding questions. 

1st coding question: (on strings)

https://www.geeksforgeeks.org/reduce-the-string-by-removing-k-consecutive-identical-characters/

• First I told the brute force approach and then the interviewer asked me to optimize it. 
• I gave him the solution using stack, and I was asked to write the code on paper. 
• Then for the second question, he asked me whether I am comfortable with Trees. I said YES, but I was actually not.
• He gave me the question: https://www.geeksforgeeks.org/find-duplicate-subtrees/

I couldn’t solve it, so he changed the question.

2nd coding question: Then he changed the question to Find the number of permutations of a given pattern in a given string.

My approach was:

• Store the frequency of each character in the pattern on a map.
• Traverse the string, like the sliding window technique, and store the frequency of each substring of the pattern’s length.
• Compare the frequencies and if it matches, increase the count of results.
• Update the frequency of the substring for every window.

The interviewer was quite impressed with my solution and I was asked to write the code for it. We had a small discussion on my projects and also his experience at Amazon.

Result: SELECTED (Got mail after a week)

Tips: 

• The only thing matters for this interview is coding questions, nothing else.
• Don’t try to think of the best approach, in the beginning, just tell out loud whatever approach you get.
• Tell them if you are stuck and they will help you. 
• Think before you say that you are confident in any topic.
• Important: Go through GFG interview experiences as many as possible. This will help you very much for any company interview.