Design Patterns in Java | Creational, Structural, Behavioral | SOLID principles

Master design patterns in Java and SOLID principles — the two topics that dominate every Java backend interview. These are the two pillars behind every successful system design interview and java interview questions & answers round at product & service-based companies.

This design patterns tutorial covers software design patterns across all three categories: creational, structural, and behavioral design patterns, with real Java examples and design pattern interview questions you'll actually face.

Creational — Singleton design pattern (including singleton class in Java and thread-safe approaches), Factory design pattern, Abstract Factory pattern, Builder pattern, and Prototype pattern

Structural design pattern — Adapter pattern, Proxy pattern, and Decorator design pattern

Behavioral patterns — Strategy design pattern (strategy pattern Java), Observer pattern in Java (observer design pattern in Java), and Chain of Responsibility pattern

Plus a dedicated deep-dive on SOLID principles in Java — what is SOLID principles, SOLID principles examples, and SOLID principles interview questions Java — so you can answer both pattern and SOLID questions confidently in any round.

Whether you're looking for design patterns in Java interview questions and answers or want to strengthen your system design thinking from the ground up, this playlist walks through every pattern with interview-focused explanations and practical code.