In Java, core concepts like OOP, exception handling, multithreading, and memory management are essential. Collections in Java (List, Set, Map, Queue) help store and manipulate data efficiently; for example, ArrayList for dynamic arrays, HashMap for key-value storage, and Set to avoid duplicates.

There was actually 3 rounds GD after that a direct CEO interview where VM will get your critical thinking capacity then Technical interview which ended up around one and a half hours