The MVVM (Model-View-ViewModel) pattern helps organize code by separating UI from business logic. This separation can improve app responsiveness by reducing UI thread workload. However, if ViewModels hold large data or perform heavy computations synchronously, it may cause frame drops below 60fps. Proper use of asynchronous data loading and lightweight ViewModels keeps memory usage moderate and battery consumption low.
To keep UI smooth, move heavy tasks out of the ViewModel's main thread using async/await or Combine framework. Use lightweight data structures and avoid retaining large objects in ViewModels. Bind UI updates efficiently by minimizing unnecessary redraws. Cache data when possible to reduce repeated processing. Profiling with Instruments helps identify bottlenecks in ViewModel logic.
MVVM itself adds minimal code overhead since it is a design pattern, not a library. However, using reactive frameworks like Combine or RxSwift with MVVM can increase bundle size. Keep dependencies minimal and use Swift's native features when possible. MVVM can improve startup time by deferring heavy data loading until after the UI appears, making the app feel faster.
On iOS, MVVM often uses SwiftUI or UIKit with Combine or async/await for data binding. iOS requires careful memory management due to ARC. Android uses Jetpack Compose or XML layouts with LiveData or Flow for MVVM. Android apps must handle lifecycle events explicitly to avoid leaks. Both platforms benefit from MVVM but use different reactive tools and lifecycle management.
MVVM does not affect store guidelines directly. However, ensure your app complies with Apple App Store rules: no private APIs, smooth UI without freezes, and proper handling of user data. MVVM helps maintain clean code, reducing bugs that could cause crashes or slowdowns flagged during review. Always test on real devices to meet performance and stability standards.
Likely, the ViewModel is doing heavy synchronous work on the main thread, blocking UI rendering. It might be loading large data or performing complex calculations without async handling. To fix this, move data fetching and processing to background threads or use async/await. Also, check if the ViewModel holds unnecessary large objects causing memory pressure.