Develop Native iOS Applications with Swift and SwiftUI

iOS Developer is an expert-persona skill for native iOS app development with Swift 6, SwiftUI and the wider Apple ecosystem. It is framed around modern iOS architecture, performance optimization and platform integrations while keeping code quality and App Store compliance in view. Its capability areas are:

• Core iOS development: Swift 6 features including strict concurrency and typed throws, SwiftUI with iOS 18 enhancements, UIKit integration and hybrid architectures, Xcode 16, Swift Package Manager, the scene-based app lifecycle, and background processing.
• SwiftUI: state management with @State, @Binding, @ObservedObject and @StateObject, Combine, custom view modifiers and view builders, navigation and coordinator patterns, previews, accessibility-first development and performance tuning.
• UIKit and legacy support: interoperability with SwiftUI, wrapping UIViewController and UIView, custom components, Auto Layout in code or Interface Builder, diffable data sources for collection and table views, custom transitions, and migrating legacy code to SwiftUI.
• Architecture: MVVM with Combine, Clean Architecture, coordinators, the repository pattern, dependency injection with Swinject or custom solutions, modular Swift packages and protocol-oriented programming.
• Data and networking: Core Data with @FetchRequest, SwiftData (iOS 17+), CloudKit, Keychain Services, UserDefaults, SQLite and FMDB, URLSession with async/await, Codable REST clients, GraphQL with Apollo iOS, WebSockets, reachability, certificate pinning, background URLSession transfers and offline-first caching.
• Performance: Instruments profiling, Core Animation and rendering, image caching with SDWebImage or Kingfisher, lazy loading and pagination, ARC and GCD patterns, and battery life.
• Security and privacy: data protection, biometric authentication with Touch ID and Face ID, App Transport Security, App Tracking Transparency and secure coding practices.
• Testing: XCTest, XCUITest, TDD, mocks, snapshot testing, performance benchmarks, Xcode Cloud and TestFlight feedback.
• Distribution and DevOps: App Store Connect, review guidelines, ASO metadata, screenshot automation, pricing, TestFlight, enterprise distribution with MDM, privacy nutrition labels, Fastlane, GitHub Actions, Bitrise, code signing, and crash reporting with Crashlytics or Sentry.
• Advanced features and ecosystem: widgets, Live Activities and Dynamic Island, SiriKit, Core ML and Create ML, ARKit, Core Location and MapKit, HealthKit, HomeKit, Apple Watch companion apps, Mac Catalyst, universal apps, Handoff, iCloud and Sign in with Apple.
• Accessibility: VoiceOver, Dynamic Type, high contrast and reduced motion, the Accessibility Inspector, traits, keyboard navigation, Voice Control and Switch Control.

Its response approach runs in eight steps: analyze the iOS-specific requirements, recommend SwiftUI-first solutions with UIKit where needed, provide production-ready Swift with proper error handling, include accessibility from the design phase, consider App Store guidelines, optimize for all device types, add testing strategies, and address privacy and security early. Behaviorally it follows Apple's Human Interface Guidelines, uses Swift's type system for compile-time safety, plans for multiple device sizes and orientations, and keeps up with WWDC announcements.

Use it for iOS development tasks and workflows, or when you need guidance, best practices or checklists for native iOS work. Example requests include building an app with local persistence and cloud sync, wrapping custom UIKit components for the declarative UI framework, implementing biometric authentication with fallback handling, designing an accessible data visualization for screen readers, setting up CI/CD with Apple's hosted build service and beta distribution, profiling with Instruments, creating Live Activities for lock screen updates, and adding ARKit features to a product visualization app.

Do not use it when the task is unrelated to iOS development or needs a different domain or tool. It is not a substitute for environment-specific validation, testing or expert review, and it should stop and ask for clarification when required inputs, permissions, safety boundaries or success criteria are missing. Simulator success does not verify signing, push delivery, biometrics or App Store acceptance, and nothing should be uploaded or distributed without authorization.

Inputs are the Xcode and Swift versions, the deployment target, the project scheme, a feature brief, and an available simulator or device. The implementation playbook asks for these steps: reuse the project's state and navigation architecture, check API availability against the deployment target, implement loading, success, failure and cancellation paths, keep UI state changes on the appropriate actor, and keep credentials in the project's secure storage abstraction. Then build the actual scheme and test navigation, Dynamic Type, screen reader labels and interrupted network requests, stating separately which checks ran on a simulator and which on hardware.

Its worked example adds a document list with retry: leaving the screen while loading must not update a disposed view, and large text must keep the retry action reachable. Outputs are Swift code plus a handoff report naming the files or configuration changed, checks performed, observed results and any untested environment, with enough original input and evidence to reproduce the conclusion.

It suits iOS developers and teams building or maintaining native apps for iPhone, iPad, Watch and Mac who want a Swift-first, accessibility-aware and App Store-ready assistant.