New Book: Swift Internals
Swift apps keep getting more ambitious. Structured concurrency, tight performance budgets, shrinking binary sizes, and modular codebases with hundreds of targets are now the norm rather than the exception. At some point, knowing the language stops being enough—you need to understand the machinery underneath it.
To help Swift developers close that gap, we're excited to announce a new Kodeco book:
A Practical Deep Dive Into Swift
Swift Internals is a hands-on exploration of how Swift actually works beneath the surface, fully up-to-date for Swift 6.2, iOS 26 and Xcode 26. Rather than rehashing the basics, the book takes you on a tour through the type system, compiler pipeline, memory model, concurrency runtime and tooling that power every Swift app you ship.
The goal isn't trivia—it's giving you the mental model you need to reason about performance, scale and correctness with confidence.
What You'll Learn
In this book you'll discover how to:
- Reason about memory layout, value vs reference semantics and how ARC really works
- Understand protocols, generics and method dispatch under the hood
- Follow Swift code through the compiler pipeline and Swift Intermediate Language (SIL)
- Work effectively with structured concurrency and Swift's execution model
- Use Unsafe Swift, metaprogramming, modular architecture and dependency graphs to build faster, more scalable apps
Each chapter pairs the underlying theory with practical examples, so the knowledge you build translates directly into better day-to-day engineering decisions.
Who This Book Is For
Swift Internals is designed for:
- iOS and macOS developers who want to move beyond "it compiles and ships"
- Engineers tackling performance, launch-time or large-codebase scaling problems
- Tech leads making architecture and modularization decisions
If you're comfortable writing day-to-day Swift and you're ready to understand why your code behaves the way it does, this is the book for you.
Meet the Author
Aaqib Hussain is an iOS engineer who has been living and breathing Swift since its first release. With over a decade of experience, he has navigated every migration from Swift 1 to modern concurrency, and he's a regular Kodeco contributor who loves teaching others about Swift's evolution. Outside of coding, you'll find Aaqib bowling, exploring new food, taking photos or travelling.
Huge thanks also to Prajwal S Belagavi, who served as final pass editor on the book.
Get the Book
We've got a lot of exciting new titles in the pipeline, and Swift Internals is the latest to land. It's the kind of book that rewards re-reading—the sort of thing you'll keep coming back to whenever you hit a tricky performance problem or want to really understand what the compiler is doing on your behalf.
As with our entire book library, subscribers get access for free, or you can purchase a copy directly from the Kodeco website for $59.99 (a paperback edition is also available on Amazon). And if you'd like to try before you buy, Chapter 1: Where the Memory Lies is free to read right now.
Ready to level up your Swift mastery?
👉 Get your copy of Swift Internals and start building faster, safer and more scalable Swift apps today.
Photo by Milad Fakurian on Unsplash