Modularizing Swift Apps with SPM
This series takes the three-layer architecture pattern (Common, Services, Features) and shows you how to apply it to a real app, step by step. Starting with a single local package, we'll add new feature domains, wire everything together in a main app, build preview apps for fast iteration, create a shared design system, and scale to a multi-package workspace.
Every post includes a companion GitHub repo with the complete working code.
The Series
1. Modularizing Swift Apps with SPM
February 26, 2026
How to split a growing iOS app into API, Domain, and Feature modules using Swift Package Manager.
2. Adding Reservations to Your Modular App
February 27, 2026
Add a second feature domain alongside Landmarks, showing how modules compose without coupling.
3. Wiring It All Together: The Main App
February 27, 2026
Build the main app target as a thin composition root that connects all your feature modules.
4. Preview Apps for Lightning-Fast Iteration
February 27, 2026
Create mini-app targets per feature so you can build and preview in isolation without compiling the full app.
5. Building a Design System Module
February 27, 2026
Extract shared UI components into a DesignSystem module that every feature can import.
6. Multi-Package Architecture
February 27, 2026
Scale beyond a single package by splitting your app into multiple SPM packages that share a common foundation.