The interview focused on:
Java Basics: OOP concepts, core Java fundamentals.
Java 8: Lambda expressions, Stream API, and Functional Interfaces.
Collection Framework: ArrayList, HashMap, and their internal workings.
Spring Boot: Basics, REST APIs, and dependency injection.
Microservices: Key concepts and communication patterns.
Design Patterns: Singleton, Factory, and Strategy patterns.
Some questions required writing code in Notepad. Overall, the interview was lengthy but thorough and insightful.