OOP (Object-Oriented Programming): I'd explain the fundamental OOP concepts such as inheritance, encapsulation, abstraction, and polymorphism. I might also give examples of applying these principles in real-world scenarios. Spring and Spring Boot: I'd highlight my experience working with Spring frameworks, emphasizing dependency injection, aspect-oriented programming (AOP), and how Spring Boot simplifies application setup with embedded servers and auto-configuration. Collections Framework: I would explain my knowledge of Java Collections, like List, Set, Map, and the advantages of using different types of collections based on the scenario (e.g., HashMap vs. TreeMap). Database Design: I would describe my experience in designing normalized databases, defining relationships between entities, and writing optimized queries using PostgreSQL/MySQL. Exception Handling: I would discuss my understanding of Java's exception hierarchy, including handling checked and unchecked exceptions using try-catch blocks and custom exceptions. Git/GitHub: I would mention my experience using version control systems like Git for collaborative development, emphasizing workflows such as branching, merging, pull requests, and handling merge conflicts in GitHub.