Worst Walmart Software Engineer 3 Interview Experience

I recently interviewed for a Software Engineer 3 position at Walmart in . The interview process consisted of two rounds. The first round focused on data structures and algorithms. I was asked two questions. The first question involved finding a repeated number in a sorted array of size n, containing numbers 1 to n-1. The second question involved finding two elements from two sorted arrays that have a sum closest to a given number. I was able to solve both questions within the expected time complexity. The second round focused on core Java concepts. The interviewer asked a wide range of theoretical questions, including the definition of Java, platform independence, primitive data types, string and string pool, collections, HashSet vs TreeSet, HashMap vs TreeMap, internal implementation of HashSet, ArrayList vs LinkedList, JVM architecture and working, garbage collection in Java, multithreading in Java, and design patterns. I answered most of the questions correctly, but I struggled with JVM architecture and forgot to make the constructor private in the singleton design pattern. The interviewer seemed impressed with my answers and discussed the work I could expect at Walmart. However, I was ultimately rejected. I found out about the rejection from a friend who referred me. The recruiters did not respond to any of my calls.