Walmart | SDE-3 (IN3) | Bangalore | April 2022 [Offer]
Summary
I interviewed for an SDE-3 position at Walmart in Bangalore and successfully received an offer after completing four rounds, despite some rescheduling issues with the hiring manager.
Full Experience
I went through a total of four rounds for the SDE-3 position at Walmart.
The first round was an online assessment conducted on HackerEarth, consisting of 5 Java MCQs and 2 DSA questions. While I don't vividly recall the exact DSA problems, they were related to Dynamic Programming and Strings.
The second round focused heavily on Data Structures/Algorithms and Java. I was asked to solve the 'Longest Substring Without Repeating Characters' problem and the interviewer expected the optimal solution. Additionally, there were numerous Java questions covering basics and multithreading. These included: different ways to create threads and their pros/cons (implementing Runnable vs. extending Thread), the differences between final, finally, and finalize, questions on Private/Final access modifiers, overriding/overloading concepts, String/StringBuilder/StringBuffer, Exceptions, how to create and demonstrate a deadlock using two threads, Daemon Threads and their creation, synchronization techniques, the Singleton pattern with a detailed discussion on double locking, Thread locks, and an in-depth discussion on Garbage Collection and its workings.
The third round was with the Hiring Manager, which unfortunately faced two reschedules due to the HM's unavailability. Eventually, it happened, and mostly behavioral questions (about 5-6) were asked. I also tackled a debugging question: 'If a customer calls and reports that a webpage is not working on your website, how would you debug it?' I provided 10-12 points for this scenario. Questions related to my current work and daily coding time, along with the values I follow in my work, were also discussed.
Finally, the fourth round was a 30-minute HR discussion which was mostly behavioral and informal. We also covered benefits, salary structure, culture, office perks, lunch, and accommodations at Walmart. I received verbal confirmation of the offer during this round.
I received the official offer letter four days later.
Interview Questions (12)
Longest Substring Without Repeating Characters
Given a string s, find the length of the longest substring without repeating characters.
Java Thread Creation and Management
Discuss the different types of ways to create threads in Java and provide a detailed discussion on the pros and cons of implementing Runnable versus extending Thread. Additionally, explain Daemon Threads and how to create one.
Java Keywords and Access Modifiers
Explain the usage and differences between final, finally, and finalize in Java. Discuss questions on Private/Final access modifiers and the concepts of Overriding/Overloading.
String Handling in Java
Discuss the differences and use cases for String, StringBuilder, and StringBuffer in Java.
Java Exceptions
Discuss questions on Exceptions in Java, including their hierarchy and handling mechanisms.
Deadlock in Java
What is a deadlock? Write a code to create a deadlock using 2 threads.
Java Synchronization Techniques
Discuss synchronization techniques in Java.
Singleton Pattern and Double-Checked Locking
Discuss the Singleton pattern and provide a detailed discussion on double-checked locking.
Thread Locks in Java
Discuss thread locks in Java.
Java Garbage Collection
Provide a detailed discussion on Garbage Collection and how it works in Java.
Webpage Debugging Scenario
If a customer calls and reports that a webpage is not working on your website, how would you debug it?
Behavioral Questions on Work and Values
Questions related to my current work and how much time I spend in my day doing coding. Also, what values I follow in my work.
Preparation Tips
My preparation focused heavily on Data Structures and Algorithms, practicing a wide range of problems on platforms like LeetCode. I also dedicated significant time to strengthening my core Java concepts, particularly multithreading, concurrency, and common design patterns such as the Singleton pattern. For behavioral rounds, I prepared by reflecting on my past experiences, anticipating common questions about teamwork, problem-solving, and my professional values, ensuring I could provide structured and concise answers.