Enforce TDD workflow for Kotlin. Write Kotest tests first, then implement. Verify 80%+ coverage with Kover.

Expo SDK 51+ and React Native specialist for cross-platform iOS and Android apps with TypeScript. Covers Expo Router (file-based navigation, deep linking, layouts), EAS Build and EAS Submit (cloud builds, code signing, store submission), Expo Dev Client, OTA updates with EAS Update, native modules and config plugins, Reanimated 3 + Gesture Handler animations, expo-router authentication patterns, push notifications (expo-notifications), in-app purchases, secure storage, and React Native New Architecture (Fabric, TurboModules). Use when building or migrating React Native apps with Expo, working with .tsx/.jsx mobile screens, or configuring EAS pipelines.

Flutter 3.x and Dart 3 cross-platform specialist for iOS, Android, web, and desktop apps with a single codebase. Covers widget composition (Stateless/Stateful, hooks, slivers), state management (Riverpod, Bloc, Provider, Signals), navigation (go_router, Navigator 2.0), HTTP/API integration (dio, http, GraphQL), local persistence (Hive, Isar, SQLite, SharedPreferences), platform channels for native code, animations (implicit/explicit, Hero, Rive/Lottie), Material 3 + Cupertino theming, accessibility, and CI/CD with Codemagic/GitHub Actions. Use when building cross-platform mobile/web/desktop apps with Flutter or working with .dart files.

Tauri 2.0 cross-platform desktop specialist for Windows, macOS, and Linux. Builds lightweight native apps with web frontends (React/Vue/Svelte) and Rust backends, using IPC commands, WebView system bindings, native system tray, file dialogs, notifications, auto-updater, and code signing. Expert in app bundle optimization (~3MB vs Electron 100MB+), permissions/CSP, plugin system, and tauri.conf.json configuration. Use when building cross-platform desktop apps that need minimal footprint, native OS integration, and Rust performance.

Apple FoundationModels framework for on-device LLM — text generation, guided generation with @Generable, tool calling, and snapshot streaming in iOS 26+.

Kotlin Coroutines and Flow patterns for Android and KMP — structured concurrency, Flow operators, StateFlow, error handling, and testing.

Idiomatic Kotlin patterns, best practices, and conventions for building robust, efficient, and maintainable Kotlin applications with coroutines, null safety, and DSL builders.

Kotlin testing patterns with Kotest, MockK, coroutine testing, property-based testing, and Kover coverage. Follows TDD methodology with idiomatic Kotlin practices.

iOS 26 Liquid Glass design system — dynamic glass material with blur, reflection, and interactive morphing for SwiftUI, UIKit, and WidgetKit.

Mobile app store deployment coordination pattern library for iOS and Android — end-to-end release workflow from dev build to public listing. Covers the complete pipeline: version management (semver + build number auto-increment), feature flags for staged rollouts, release branch strategies (git flow for mobile), internal QA on TestFlight + Play Console Internal Testing, beta distribution (TestFlight External + Play Console Closed Testing), final App Store / Play Store submission with Apple review + Google Play review processes, phased rollout strategies (iOS phased release, Play Console staged rollout), hotfix flows (iOS expedited review vs EAS Update OTA, Play Console halted rollout), and cross-platform release synchronization. Use when planning a mobile release, coordinating iOS + Android releases in parallel, handling hotfixes, or setting up a mobile CI/CD pipeline. Orchestrates the specialized deploy-eas, deploy-app-store, and deploy-play-store skills (in atum-workflows) into a single release workflow that ATUM agency can repeat on every mobile client project.

Setup Sentry in iOS/Swift apps. Use when asked to add Sentry to iOS, install sentry-cocoa SDK, or configure error monitoring, tracing, session replay, logging, or profiling for iOS applications using Swift and SwiftUI.

Thread-safe data persistence in Swift using actors — in-memory cache with file-backed storage, eliminating data races by design.

Swift 6.2 Approachable Concurrency — single-threaded by default, @concurrent for explicit background offloading, isolated conformances for main actor types.

Protocol-based dependency injection for testable Swift code — mock file system, network, and external APIs using focused protocols and Swift Testing.

SwiftUI architecture patterns, state management with @Observable, view composition, navigation, performance optimization, and modern iOS/macOS UI best practices.