Krzysztof Magiera(@kzzzf):SwiftUI isn’t native and here’s why SwiftUI apps may sometimes feel janky. It ditches the key element that made animations run so smoothly on iOS since the original iPhone: Core Animation. In SwiftUI animations run in-app without CA backing. Block the main thread: SwiftUI ball stalls while UIKit’s keeps moving on the render server.

Krzysztof Magiera

@kzzzf

R&D @swmansion. Made react-native (@meta), reanimated, rn-screens, Radon IDE,

Joined May 2015

609 Following 15.1K Followers

Krzysztof Magiera@kzzzf

2026.09.15 22:15

SwiftUI isn’t native and here’s why SwiftUI apps may sometimes feel janky. It ditches the key element that made animations run so smoothly on iOS since the original iPhone: Core Animation. In SwiftUI animations run in-app without CA backing. Block the main thread: SwiftUI ball stalls while UIKit’s keeps moving on the render server.