Interview Experience - 149 - Walmart | Software Engineer-3 | L3
Summary:
📌 Job Role: Software Development Engineer
🔢 Number of Rounds: 4
📜 Offer Status: Offer
📍 Location: Bangalore
👤 Candidate Name: Not disclosing due to signed NDA
Interview Process
The interview process at Walmart consisted of four rounds:
Technical Round (1 hour 20 minutes)
Technical Round (1 hour)
Hiring Manager Round (45 minutes)
HR Round (20 minutes)
The process was well-structured, starting with core technical evaluations, followed by a discussion on system design and project architecture, then behavioral and managerial aspects, and finally, HR-related discussions.
The candidate received an offer approximately two weeks after completing all the rounds.
Preparation Guide
The candidate did not explicitly mention any specific preparation sources. However, based on the interview questions, it is recommended to prepare the following areas:
Data Structures and Algorithms (DSA): Practice problems on platforms like LeetCode.
Java: Core concepts, Java 8 features, collections, concurrency, and streams.
Spring Framework: Dependency Injection, bean scopes, annotations, and Spring Boot.
Databases: SQL queries, joins, and query optimizations.
System Design: Low-level and high-level design concepts.
AWS (IAM): Only if it is relevant to your profile.
Interview Rounds
Round 1: Technical
Duration: 80 minutes
Difficulty Level: Medium
Experience:
The interview began with a discussion on the candidate's current projects and contributions in their organization. After this, the interviewer moved to coding and technical questions spanning various areas like DSA, Java, Spring, databases, and AWS.
Key questions asked during the round:
Given a list of countries, count the number of occurrences of each country and print them in ascending order of names.
Given a list of names, print the names which don't start with 'a' using Java Stream APIs.
Difference between
waitandsleepmethods in Java.Write an SQL query to list employees who are not assigned any project (without using nested queries).
Explain Dependency Injection and different Spring bean scopes.
Use of
@Qualifierannotation in Spring.How to define a step-scope bean in Spring.
Difference between
@Component,@Controller, and@Repositoryannotations.Why static and default methods were introduced in Java 8.
Given two interfaces with the same default method, and a class implementing both, which default method will be used?
What is a Binary Search Tree (BST)?
Difference between BFS and DFS.
When to use LinkedList over ArrayList.
Method overloading vs overriding, abstract class vs interfaces.
Mapping database tables using Hibernate annotations (
@Entity,@Table,@Column).Write a REST API for saving employee details in a database and discuss MVC pattern.
TreeMap vs LinkedHashMap vs HashMap.
What is IAM in AWS (specific to resume mention).
Comparable vs Comparator interfaces and their use cases.
Key Learnings:
Be prepared for a balanced mix of coding and conceptual questions.
Focus on Java 8 features, Spring annotations, and database queries.
DSA practice is essential to solve problems efficiently.
Having a clear understanding of core Java and backend frameworks is crucial.
Round 2: Technical
Duration: 60 minutes
Difficulty Level: Medium
Experience:
This round was primarily focused on system design and deeper technical concepts. The interviewer started by asking the candidate to design a Twitter Search Engine.
Follow-up discussions included:
Questions on ElasticSearch since it was used in the design.
Vertical vs horizontal scaling, consistent hashing, database partitioning, and load balancing.
Parent POM in Maven and why it is used.
How JAR files reference other JAR files.
Debugging a
ClassNotFoundExceptionwhen the class exists in the referenced JAR.Difference between JAR and WAR files.
Synchronization in Java.
Modifications to make HashMap O(N) in time complexity.
Spring vs Spring Boot.
Benefits of using Hibernate.
Detailed discussion on the candidate’s current project architecture.
Key Learnings:
Brush up on system design concepts, especially search engine design and related components like ElasticSearch.
Be ready for questions related to scalability, distributed systems, and debugging scenarios.
Understand Maven, JAR/WAR files, and Java internals.
Be confident in explaining your project architecture clearly.
Round 3: Hiring Manager
Duration: 45 minutes
Difficulty Level: Medium
Experience:
The hiring manager round started with an introduction and a discussion on the candidate’s current projects, roles, and responsibilities. The manager also explained about the team structure and the projects that the candidate would be working on if selected.
Behavioral and situational questions included:
How would you handle last-minute requirements that need to be delivered quickly?
As one of the founding members of a new team, how would you approach building the team?
Key Learnings:
Be prepared to explain your current projects and responsibilities in detail.
Think of concrete examples where you have handled pressure or contributed to team building.
Show clarity in how you handle ownership and adapt to fast-changing requirements.
Round 4: HR
Duration: 20 minutes
Difficulty Level: Easy
Experience:
The HR round covered typical HR questions and discussions on company policies. Topics included:
Why do you want to change your job?
Why Walmart?
The HR also discussed salary structure, perks, and other company policies.
Key Learnings:
Be clear and honest about your reasons for changing jobs.
Research the company beforehand to answer "Why Walmart?" effectively.
Be ready to discuss salary expectations professionally.
Final Thoughts
The interview process at Walmart is thorough, evaluating both technical depth and behavioral fit.
Key Takeaways for Future Candidates:
Strong fundamentals in DSA, Java, and Spring are critical.
Prepare for system design interviews and be comfortable with explaining project architecture.
Practice database queries and be familiar with annotations in Hibernate.
Be ready for behavioral questions that assess team collaboration and problem-solving in dynamic situations.
Finally, ensure clarity on why you want to join Walmart, as this is discussed in the HR round.