Design Patterns: Reusable Solutions for Scalable Systems
Overview
Design patterns are time-tested, reusable solutions to common software design problems, enabling modular, maintainable, and scalable code. In this hub, we cover all 23 Gang of Four (GoF) patterns — creational, structural, and behavioral — along with modern patterns like Dependency Injection, Repository, Event Sourcing, and CQRS.
By mastering these patterns, you’ll learn how to design elegant, extensible Java systems and apply them in real-world projects, from e-commerce platforms to distributed microservices.
Learning Objectives
- Master creational patterns (e.g., Singleton, Factory, Builder, Prototype) for object creation.
- Learn structural patterns (e.g., Adapter, Decorator, Proxy, Bridge, Composite, Flyweight, Facade) for object composition.
- Apply behavioral patterns (e.g., Strategy, Observer, Command, State, Chain of Responsibility, Template Method, Mediator, Memento, Iterator, Interpreter, Visitor) for dynamic behavior.
- Explore modern enterprise patterns (e.g., Dependency Injection, Repository, Event Sourcing, CQRS).
- Design scalable systems using patterns, UML, and clean code.
Lessons
Introduction
Introduction to Design Patterns (15 min)
Start Lesson →Classification of Design Patterns (15 min)
Start Lesson →
Creational Patterns (5 GoF)
Singleton Pattern (15 min)
Start Lesson →Factory Method Pattern (20 min)
Start Lesson →Abstract Factory Pattern (20 min)
Start Lesson →Builder Pattern (20 min)
Start Lesson →Prototype Pattern (20 min)
Start Lesson →
Structural Patterns (7 GoF)
Adapter Pattern (15 min)
Start Lesson →Decorator Pattern (20 min)
Start Lesson →Facade Pattern (15 min)
Start Lesson →Composite Pattern (20 min)
Start Lesson →Proxy Pattern (20 min)
Start Lesson →Bridge Pattern (20 min)
Start Lesson →Flyweight Pattern (20 min)
Start Lesson →
Behavioral Patterns (11 GoF)
Strategy Pattern (20 min)
Start Lesson →Observer Pattern (20 min)
Start Lesson →Command Pattern (20 min)
Start Lesson →Template Method Pattern (15 min)
Start Lesson →State Pattern (20 min)
Start Lesson →Chain of Responsibility Pattern (20 min)
Start Lesson →Mediator Pattern (20 min)
Start Lesson →Memento Pattern (20 min)
Start Lesson →Iterator Pattern (15 min)
Start Lesson →Interpreter Pattern (20 min)
Start Lesson →Visitor Pattern (20 min)
Start Lesson →
Modern Patterns
Dependency Injection (20 min)
Start Lesson →Repository Pattern (20 min)
Start Lesson →Event Sourcing (20 min)
Start Lesson →CQRS (Command Query Responsibility Segregation) (20 min)
Start Lesson →
Capstone
- Mock Interview: Applying Patterns (30 min)
Start Lesson →
Start Your Journey
Ready to build reusable, scalable systems with design patterns? Dive into Introduction to Design Patterns to begin, or explore other sections to continue your journey as a better software engineer.