Where Errors Belong: Use Case Outputs, Not Error Passed Around
Published on 03 June 2026Most apps leak Error across boundaries and downcast in ViewModels. Model failures in the use case output vocabulary instead. Swift and Kotlin.
Practical software architecture and design for iOS engineers.
Most apps leak Error across boundaries and downcast in ViewModels. Model failures in the use case output vocabulary instead. Swift and Kotlin.
Understand factories, builders, and composition roots in Swift, and learn where each construction pattern belongs.
Learn how to refactor an iOS feature toward better architecture gradually, without rewriting the whole app.
Learn when the Repository pattern helps Swift apps, when it becomes a wrapper, and how to design useful data boundaries.
Learn when use cases help iOS architecture, when they add noise, and how to keep them focused in Swift apps.
Learn how to test architecture in Swift by focusing on behavior, boundaries, contracts, and meaningful composition.
Learn dependency injection in Swift without ceremony using initializers, factories, environment values, and composition roots.
Learn why Swift protocols are not architecture by themselves, and how to use them as meaningful boundaries.