Walmart | Software Engineer-3 (IN3) | | May [Offer]

Background: Current Company: Product based fintech company YOE: 4.7 Years

Round -1: Technical (1 hour 20 minutes)

The interview started with a discussion on projects I worked on in my current company. Then I was asked two DSA questions and some questions related to Java.

1. Move Zeros to the end: Move Zeroes (Leetcode)
2. Maximum Subarray Sum: Maximum Subarray (Leetcode)
3. You are given a list of countries, count the number of occurrences of each country and print them in ascending order of names.
4. You are given a list of names, print the names which don't start from 'a' using Java Stream APIs.
5. Difference between wait and sleep methods.
6. You are given two tables: project and employee, Write a query to list down names of employees who are not assigned any project. Do not use a nested query to solve this.
7. What is dependency injection? Discussion on different Spring bean scopes.
8. Use of @Qualifier annotation.
9. How you will define a step scope bean.
10. What is the difference between @Component, @Controller and @Repository annotation
11. Why were static and default methods in interfaces introduced in Java 8
12. Given two interfaces which have the same default method, there is one class implementing both the interfaces. Which default method will be part of this class.
13. What is a Binary Search Tree.
14. Difference between BFS and DFS.
15. When you will use LinkedList over ArrayList.
16. Discussion on Method Overloading, Overriding, Abstract class and Interfaces.
17. How to map database tables in Hibernate. @Entity, @Table, @Column annotations.
18. Write a REST API for saving employees' details in the database. Discussion on the MVC pattern.
19. TreeMap vs LinkedHashMap vs HashMap.
20. What is IAM in AWS? (AWS was in my CV, so this question was asked).
21. Comparable vs Comparator Interface and when to use which one.

Round 2: Technical (1 hour)

1. Design Twitter Search Engine.
2. Some questions on Elastic Search as I used it for designing the Twitter Search Engine.
3. Discussion on vertical vs horizontal scaling, consistent hashing, database partitioning and load balancing.
4. What is Parent POM and why do we use it.
5. How does a jar file reference other jar files.
6. You are getting ClassNotFoundException. You see that the class is present in the jar file you are referencing. How will you debug it.
7. Jar vs WAR file.
8. Synchronization in Java.
9. What modification will you make to HashMap to make it an O(N) time complexity.
10. Spring vs Spring boot.
11. Benefits of using hibernate.
12. Discussion on my current Project Architecture.

Round 3: Hiring Manager (45 Minutes) The interview started with a brief introduction and discussion about the projects I have worked on and my roles and responsibilities in my current organization. Then the interviewer described the team I will be working with and the projects I will be working on if selected.

Some situation-based behavioral questions were asked. I can remember some of them.

1. How will you handle the requirements that came at the very last moment and need to be delivered quickly.
2. The team is very new and you are one of the founding members of the team where you also need to be involved in building the team. How will you approach this.

Round 4: HR (20 minutes)

In this round, some HR questions like why you want to change the job, why Walmart etc. were asked. Then HR discussed the salary structure and perks at the company and some other company policies.

I got the offer after two weeks of the interview process.