Senior Mobile Developer

Expert mobile application development across iOS, Android, React Native, and Flutter.

Keywords

mobile, ios, android, react-native, flutter, swift, kotlin, swiftui, jetpack-compose, expo-router, zustand, app-store, performance, offline-first

Quick Start

Scaffold a React Native project

python scripts/mobile_scaffold.py --platform react-native --name MyApp

Build for production

python scripts/build.py --platform ios --env production

Generate App Store metadata

python scripts/store_metadata.py --screenshots ./screenshots

Profile rendering performance

python scripts/profile.py --platform android --output report.html

Tools

Script Purpose

scripts/mobile_scaffold.py

Scaffold project for react-native, ios, android, or flutter

scripts/build.py

Build automation with environment and platform flags

scripts/store_metadata.py

Generate App Store / Play Store listing metadata

scripts/profile.py

Profile rendering, memory, and startup performance

Platform Decision Matrix

Aspect Native iOS Native Android React Native Flutter

Language Swift Kotlin TypeScript Dart

UI Framework SwiftUI/UIKit Compose/XML React Widgets

Performance Best Best Good Very Good

Code Sharing None None ~80% ~95%

Best For iOS-only, hardware-heavy Android-only, hardware-heavy Web team, shared logic Maximum code sharing

Workflow 1: Scaffold a React Native App (Expo Router)

• Generate project -- python scripts/mobile_scaffold.py --platform react-native --name MyApp

• Verify directory structure matches this layout: src/ ├── app/ # Expo Router file-based routes │ ├── (tabs)/ # Tab navigation group │ ├── auth/ # Auth screens │ └── _layout.tsx # Root layout ├── components/ │ ├── ui/ # Reusable primitives (Button, Input, Card) │ └── features/ # Domain components (ProductCard, UserAvatar) ├── hooks/ # Custom hooks (useAuth, useApi) ├── services/ # API clients and storage ├── stores/ # Zustand state stores └── utils/ # Helpers

• Configure navigation in app/_layout.tsx with Stack and Tabs.

• Set up state management with Zustand + AsyncStorage persistence.

• Validate -- Run the app on both iOS simulator and Android emulator. Confirm navigation and state persistence work.

Workflow 2: Build a SwiftUI Feature (iOS)

• Create the View using NavigationStack , @StateObject for ViewModel binding, and .task for async data loading.

• Create the ViewModel as @MainActor class with @Published properties. Inject services via protocol for testability.

• Wire data flow: View observes ViewModel -> ViewModel calls Service -> Service returns data -> ViewModel updates @Published -> View re-renders.

• Add search/refresh: .searchable(text:) for filtering, .refreshable for pull-to-refresh.

• Validate -- Run in Xcode previews first, then simulator. Confirm async loading, error states, and empty states all render correctly.

Example: SwiftUI ViewModel Pattern

@MainActor class ProductListViewModel: ObservableObject { @Published private(set) var products: [Product] = [] @Published private(set) var isLoading = false @Published private(set) var error: Error?

private let service: ProductServiceProtocol

init(service: ProductServiceProtocol = ProductService()) {
    self.service = service
}

func loadProducts() async {
    isLoading = true
    error = nil
    do {
        products = try await service.fetchProducts()
    } catch {
        self.error = error
    }
    isLoading = false
}

}

Workflow 3: Build a Jetpack Compose Feature (Android)

• Create the Composable screen with Scaffold , TopAppBar , and state collection via collectAsStateWithLifecycle() .

• Handle UI states with a sealed interface: Loading , Success<T> , Error .

• Create the ViewModel with @HiltViewModel , MutableStateFlow , and repository injection.

• Build list UI using LazyColumn with key parameter for stable identity and Arrangement.spacedBy() for spacing.

• Validate -- Run on emulator. Confirm state transitions (loading -> success, loading -> error -> retry) work correctly.

Example: Compose UiState Pattern

sealed interface UiState<out T> { data object Loading : UiState<Nothing> data class Success<T>(val data: T) : UiState<T> data class Error(val message: String) : UiState<Nothing> }

@HiltViewModel class ProductListViewModel @Inject constructor( private val repository: ProductRepository ) : ViewModel() { private val _uiState = MutableStateFlow<UiState<List<Product>>>(UiState.Loading) val uiState: StateFlow<UiState<List<Product>>> = _uiState.asStateFlow()

fun loadProducts() {
    viewModelScope.launch {
        _uiState.value = UiState.Loading
        repository.getProducts()
            .catch { e -> _uiState.value = UiState.Error(e.message ?: "Unknown error") }
            .collect { products -> _uiState.value = UiState.Success(products) }
    }
}

}

Workflow 4: Optimize Mobile Performance

• Profile -- python scripts/profile.py --platform <ios|android> --output report.html

• Apply React Native optimizations:

• Use FlatList with keyExtractor , initialNumToRender=10 , windowSize=5 , removeClippedSubviews=true

• Memoize components with React.memo and handlers with useCallback

• Supply getItemLayout for fixed-height rows to skip measurement

• Apply native iOS optimizations:

• Implement prefetchItemsAt for image pre-loading in collection views

• Apply native Android optimizations:

• Set setHasFixedSize(true) and setItemViewCacheSize(20) on RecyclerViews

• Validate -- Re-run profiler and confirm frame drops reduced and startup time improved.

Workflow 5: Submit to App Store / Play Store

• Generate metadata -- python scripts/store_metadata.py --screenshots ./screenshots

• Build release -- python scripts/build.py --platform ios --env production

• Review the generated listing (title, description, keywords, screenshots).

• Upload via Xcode (iOS) or Play Console (Android).

• Validate -- Monitor review status and address any rejection feedback.

Reference Materials

Document Path

React Native Guide references/react_native_guide.md

iOS Patterns references/ios_patterns.md

Android Patterns references/android_patterns.md

App Store Guide references/app_store_guide.md

Full Code Examples REFERENCE.md