Design Patterns

Introduction #

Design patterns are proven solutions to recurring software design problems. They represent best practices that developers can apply to improve code structure, maintainability, and scalability. Design patterns help in writing clean, reusable, and efficient code.

Why Use Design Patterns? #

• Improves Code Readability – Makes the software structure clearer and easier to understand.
• Enhances Maintainability – Facilitates updates and modifications with minimal effort.
• Promotes Reusability – Provides standardized solutions that can be applied to multiple projects.
• Encourages Best Practices – Enforces well-established software development principles.

Types of Design Patterns #

Design patterns are generally classified into three categories:

1. Creational Patterns – Focus on object creation mechanisms, improving flexibility and reuse.
   Examples: Factory Method, Singleton, Builder, Prototype.
2. Structural Patterns – Help organize classes and objects to form larger structures.
   Examples: Adapter, Bridge, Composite, Decorator, Proxy.
3. Behavioral Patterns – Define how objects interact and communicate.
   Examples: Observer, Strategy, Command, State, Mediator.

Architectural Design Patterns #

Architectural design patterns focus on the high-level structure of a software system. They define the overall system architecture and how components interact.

Examples of Architectural Design Patterns #

1. Microservices Architecture – Divides applications into small, independent services that communicate over a network.
2. Layered Architecture – Organizes code into layers (e.g., presentation, business logic, data access).
3. Event-Driven Architecture – Uses events to decouple system components for better scalability and responsiveness.
4. CQRS (Command Query Responsibility Segregation) – Separates read and write operations to optimize performance.
5. Reporting Database Pattern – Separates transactional and analytical workloads to improve efficiency.