Company: Walmart Global Tech India | SDE2(Frehser) | Oncampus hiring for Batch 2023
Education: 4th year BTech student from IIITD/NSUT/DTU/IITD
Date: Aug 2022

There were three rounds in total. The 1st was a technical round, 2nd one was a DSA round, and the last was an HR round.

1st Round(Technical): 45-50 mins over zoom: (Level : Easy)

1. At first, the interviewer asked me to tell him about myself.
2. Then he asked me to introduce my one Internship project briefly. I had developed a React App and mostly worked on the frontend part of it, so we talked more deeply about my work and how I did them. (Be ready for the counter questions here).
3. Then a coding question, given a list of IPv4 addresses, checks if they are valid or not. You should return a boolean array, array[i] = true if its IPv4 address is correct; otherwise, false. I explained my logic and coded it. Then he asked me to handle all possible errors that could be there, like validating inputs.
4. Then he asked me basic CN questions like what happens when you search google.com on your web browser.
5. Difference btw ArrayList and LinkedList, and where would you use them?
6. Difference btw BST and LinkedList, and where would you use them?
7. Difference btw abstract class and interfaces, and where would you use them?

2nd Round(DSA) : 45-50 mins over zoom : (Level: Easy-Medium)

1. The interviewer asked which Data Structure you are most comfortable in. I said Trees. So she asked me for a variation of https://leetcode.com/problems/two-sum-iv-input-is-a-bst/. She asked me to find the count of pairs with the given sum k. I explained the Inorder approach with O(N) time and O(N) space. She was satisfied but told me that you could improve on space. So I gave her O(Nh) time and O(h) space complexity solution. She was happy with that. I coded both approaches.
2. Then she asked me a famous leetcode question: https://leetcode.com/problems/gas-station/. I explained my approach and coded it with time complexity: O(n) and O(1) space.

3rd round (HR Round): 40 mins over zoom:

1. She asked me how my day was, then told me to brief myself.
2. Then she asked me about my Internship projects, and we went a bit more in-depth in it. (Be prepared for some counter questions here, like what chalenges you faced and how you solved them. )
3. Then she asked me about my strengths and weaknesses. (Try to be yourself while answering this. Do not simply copy the answer from the Internet).
4. Then she asked me about one thing I was not happy about and how my life would be if I had what I expected. I told her that I was a CS enthusiast but got ECE due to my low JEE Mains score. So I told her how I felt initially and how this motivated me even more, to explore the CS domain and excel in it. She was delighted after listening to it.

My suggestions :

1. Be confident while explaining your approach.
2. Speak clearly without any hesitation.
3. Be yourself while answering HR questions, cuz they will know if you are lying.
4. Leetcode is sufficient for DSA.
5. Read CS fundamentals like CN, DBMS, OS, OOP.