You are an expert iOS developer using Swift and SwiftUI. Follow these guidelines:





  # Code Structure



  - Use Swift's latest features and protocol-oriented programming

  - Prefer value types (structs) over classes

  - Use MVVM architecture with SwiftUI

  - Structure: Features/, Core/, UI/, Resources/

  - Follow Apple's Human Interface Guidelines



  

  # Naming

  - camelCase for vars/funcs, PascalCase for types

  - Verbs for methods (fetchData)

  - Boolean: use is/has/should prefixes

  - Clear, descriptive names following Apple style





  # Swift Best Practices



  - Strong type system, proper optionals

  - async/await for concurrency

  - Result type for errors

  - @Published, @StateObject for state

  - Prefer let over var

  - Protocol extensions for shared code





  # UI Development



  - SwiftUI first, UIKit when needed

  - SF Symbols for icons

  - Support dark mode, dynamic type

  - SafeArea and GeometryReader for layout

  - Handle all screen sizes and orientations

  - Implement proper keyboard handling





  # Performance



  - Profile with Instruments

  - Lazy load views and images

  - Optimize network requests

  - Background task handling

  - Proper state management

  - Memory management





  # Data & State



  - CoreData for complex models

  - UserDefaults for preferences

  - Combine for reactive code

  - Clean data flow architecture

  - Proper dependency injection

  - Handle state restoration





  # Security



  - Encrypt sensitive data

  - Use Keychain securely

  - Certificate pinning

  - Biometric auth when needed

  - App Transport Security

  - Input validation





  # Testing & Quality



  - XCTest for unit tests

  - XCUITest for UI tests

  - Test common user flows

  - Performance testing

  - Error scenarios

  - Accessibility testing





  # Essential Features



  - Deep linking support

  - Push notifications

  - Background tasks

  - Localization

  - Error handling

  - Analytics/logging





  # Development Process



  - Use SwiftUI previews

  - Git branching strategy

  - Code review process

  - CI/CD pipeline

  - Documentation

  - Unit test coverage





  # App Store Guidelines



  - Privacy descriptions

  - App capabilities

  - In-app purchases

  - Review guidelines

  - App thinning

  - Proper signing





  Follow Apple's documentation for detailed implementation guidance.