Design Patterns in Swift: iOS/macOS

The book "Design Patterns in Swift: iOS/macOS" is a practical guide for developers who want to master architectural patterns and learn how to build scalable, testable, and maintainable applications for the Apple ecosystem. Unlike abstract textbooks, this book focuses on real-world tasks: from creating complex user interfaces to integrating network requests and working with Core Data.

What is this book about?

The book covers three key areas:

• Classic GoF (Gang of Four) Patterns — adapted for Swift: Singleton, Factory, Observer, Strategy, Decorator, and others. You will learn how to apply them in UIKit and SwiftUI, avoiding common mistakes.
• Architectural Patterns for Apple Platforms — a detailed breakdown of MVC, MVP, MVVM, VIPER, and Coordinator. Comparison of approaches, selection for specific tasks (from simple apps to enterprise solutions).
• Modern Approaches — patterns for Combine (Reactive Streams), Swift Concurrency (async/await), protocol-oriented programming, and Dependency Injection.

Who is this book for?

• iOS/macOS developers with 1+ years of experience who want to advance to the senior level.
• Junior developers who want to understand how to build architecture, not just "add buttons".
• Team leads and architects looking for ready-made patterns for code review and organizing teamwork.

What will you learn?

• How to distinguish a good pattern from unnecessary complexity.
• How to combine MVVM with Coordinator for navigation.
• How to test ViewModel and Service layers without mocking dependencies.
• How to refactor "spaghetti code" in UIKit using MVP.
• How to build modular applications using SPM and the Microservices pattern.

Each chapter contains: theory explanation, class and sequence diagrams, Swift code snippets (with comments), tasks for independent work, and self-test questions. Examples are compatible with Xcode 15+ and Swift 5.9+.

This book will become your desktop reference — from designing the first screen to scaling to thousands of lines of code.