Frontend / Mobile Engineer — Native iOS + Android, React Native (Secure Healthcare App)

We're looking for a senior mobile engineer with real native iOS and Android depth to build the mobile experience for a secure healthcare app. The mobile app is the main product, and the standout features — Apple Wallet passes, home-screen widgets, Live Activity / Dynamic Island — are native OS extensions that can't be built in JavaScript. This is not a "React dev who also does some mobile"; it's a real mobile engineer. The app serves healthcare field representatives who need secure mobile workflows for managing documents, credentials, status visibility, and access in the field. What you'll own: - Web: React + TypeScript, working against an API client generated from the backend so the two never drift - Mobile (cross-platform): React Native + Expo for shared app UI and logic - Mobile (native): the real differentiators — Apple Wallet passes (PassKit), home-screen widgets (WidgetKit), Live Activity / Dynamic Island (ActivityKit) — native iOS (Swift) and Android (Kotlin) - On-device security: storing credentials safely with platform secure storage (Keychain/Secure Enclave on iOS, Keystore/StrongBox on Android) Must have: - React and TypeScript (modern hooks, a server-cache library like TanStack Query) - React Native and Expo, ideally on the current New Architecture - Real native iOS (Swift) and Android (Kotlin) experience, not just JS wrappers - App Store / TestFlight / Play Console release experience - On-device secure storage (Keychain/Keystore) awareness Strongly preferred: - Apple platform extensions: PassKit, WidgetKit, ActivityKit (Live Activity) - Working against a generated / contract-driven API client - Monorepo and shared-package experience - Front-end testing discipline