Software Architecture and Design Patterns

[Buela_Vigneswaran]

Software Architecture and Design Patterns

1. Software Architecture

• Definition: The high-level structure of a software system, defining its components and their interactions.
• Key Concepts:
  • Architectural styles (e.g., Client-Server, Microservices, Event-Driven, Service-Oriented Architecture [SOA], Layered Architecture).
  • Non-functional requirements: Scalability, Reliability, Security, and Maintainability.
  • Middleware and APIs.

2. Common Software Architecture Patterns

• Monolithic Architecture:
  • Single, unified codebase.
  • Suitable for small to medium-sized applications.
  • Challenges: Difficult to scale and maintain as the system grows.
• Microservices Architecture:
  • Applications split into small, loosely coupled services.
  • Independent deployment and scalability.
  • Challenges: Network overhead, managing inter-service communication.
• Event-Driven Architecture:
  • Communication through events.
  • Suitable for real-time systems and asynchronous processes.
  • Examples: Kafka, RabbitMQ.

3. Design Patterns

• Definition: Reusable solutions to common software design problems.
• Types of Design Patterns:
  • Creational Patterns:
    • Focus on object creation mechanisms.
    • Examples: Singleton, Factory Method, Abstract Factory, Builder, Prototype.
  • Structural Patterns:
    • Deal with object composition.
    • Examples: Adapter, Bridge, Composite, Decorator, Facade, Proxy.
  • Behavioral Patterns:
    • Focus on object interaction and communication.
    • Examples: Observer, Strategy, Command, State, Iterator, Mediator.

4. Principles of Good Design

• SOLID Principles:
  • S: Single Responsibility Principle (SRP)
  • O: Open/Closed Principle (OCP)
  • L: Liskov Substitution Principle (LSP)
  • I: Interface Segregation Principle (ISP)
  • D: Dependency Inversion Principle (DIP)
• DRY (Don’t Repeat Yourself)
• KISS (Keep It Simple, Stupid)
• YAGNI (You Aren’t Gonna Need It)

5. UML Diagrams (Unified Modeling Language)

• Used to represent system designs visually.
• Examples: Use Case Diagrams, Class Diagrams, Sequence Diagrams, Activity Diagrams.

6. Key Tools for Architecture and Design

• Modeling Tools: Enterprise Architect, Visual Paradigm.
• Diagramming Tools: Lucidchart, Draw.io, Microsoft Visio.