UIKit

Wholesale adoption of SwiftUI to rewrite large, long-lived applications introduces significant business risk. Incremental migration strategies focusing only on the view layer while preserving UIKit navigation are recommended but require more planning than big-bang rewrites.

The Preview feature in SwiftUI requires building the entire project and fails with compatibility errors when UIKit is present in the codebase. This prevents developers from using Previews to speed up development in mixed UIKit/SwiftUI projects.