Walmart || Software Engineer III || Rejected

I recently appeared for the Software Engineer III role at Walmart. I have over 3 years of experience at a product-based MNC. The interview process involved two one-hour rounds.

Coding Round: This round began with introductions and project discussions. The interviewer then asked three easy LeetCode coding questions:

• Maximum Average Subarray I
• Odd Even Linked List
• Binary Tree Right Side View I was able to provide an optimized solution for all of them, starting with a brute-force approach. This round went quite well.

LLD and Java Round: This round also started with introductions and a discussion about my projects. Following that, I was asked one coding question:

• 3Sum I managed to write an optimized solution for this as well, after presenting a brute-force one. After the coding question, the interviewer delved into several Java and technical questions:
• Kafka Pros & Cons and Packet Size: What are the advantages and disadvantages of Kafka? What is the Kafka packet size limit?
• JDBC vs. Hibernate: Compare JDBC and Hibernate. I couldn't elaborate much here as I've primarily used JPA or Hibernate in my projects, not JDBC directly.
• Checked vs. Unchecked Exceptions: Explain the difference between checked and unchecked exceptions in Java.
• Sending Large Data to Client (Non-SFTP): Apart from SFTP, what are other methods to send large data to a client?
• Detecting File Corruption During Transfer: If a few bits get corrupted while sending a file to a client, how can you identify them? I suggested using a file checksum.
• Java Version Improvements (8 to 11 to 17): Discuss the key improvements and features introduced from Java 8 to Java 11, and then to Java 17.
• Internal Working of HashMap: Explain the internal working mechanism of a HashMap in Java.
• JVM Memory Model: Explain the Java Virtual Machine (JVM) memory model.
• Garbage Collection & Object Eligibility: Describe Java's Garbage Collection process and the ways to make an object eligible for garbage collection.
• Garbage Collection Types & Use Cases: What are the different types of Garbage Collectors in Java, and what are their respective use cases?
• Major and Minor GCs in G1 Garbage Collector: Explain the concepts of major and minor garbage collections within the G1 Garbage Collector. I knew G1 GC and its use cases but was not aware of major and minor in G1 GC. I feel that's quite a minor detail unless one needs to know these specifics.
• Project Deadlock Scenario: Describe any situation where you faced a deadlock in a project. I couldn't recall any such scenario at the moment.

Interestingly, there were no Low-Level Design (LLD) questions, which I had prepared for. I managed to answer about 80% of the questions. The remaining 20% felt like very minor details or scenario-based questions, such as the Kafka packet size limit, major/minor G1 GC, or specific deadlock situations I'd encountered.

I received a rejection email at the end of the day. I requested feedback, and the recruiter mentioned she would share detailed feedback in a couple of days, but it never arrived. My guess is that my performance in the second round wasn't satisfactory for them.