Senior React Native Expert (SME): Expo Bare Workflow migration

We need a React Native Subject Matter Expert: the person we can turn to for the right answer on anything modern-RN: architecture, native modules, the New Architecture (Fabric/TurboModules/JSI), EAS/build tooling, performance, security, and store delivery. Someone who has done it for real, can justify decisions with facts and trade-offs, and can level up our internal team. To prove fit and deliver immediate value, the first project is completing an in-progress Expo Bare Workflow migration of our live app. This is a real, high-standard codebase, so it's an ideal way to demonstrate your expertise while shipping something we need. Strong collaboration here leads to an ongoing SME relationship (architecture reviews, library upgrades, new native features, multi-tenant expansion, consulting on Firebase Crashlytics issues). This is a remote contract engagement (not full-time employment). We scope the migration as the first milestone-based project, with continued SME work expected to follow. As our React Native SME you will: 1. Be the go-to authority on modern React Native - answer hard technical questions quickly and correctly, with limited research time. 2. Own architecture decisions: recommend and justify library/tooling/pattern choices (and when to write custom native code vs. adopt a library vs. patch one). 3. Set and uphold standards: define conventions, review code/architecture, and raise the quality bar (testing, security, performance). 4. Stay ahead of the curve: track RN releases, the New Architecture, Expo SDK changes, and bring relevant improvements to us. 5. Level up our team: document patterns and decisions so our internal engineers can build and maintain confidently after handoff - including AI-assisted (Claude Code / Cursor) workflows, which we use heavily. 6. De-risk the hard stuff: native build failures, WebRTC, FCM, IAP, signing/store compliance - the things that block non-experts. First Project: Complete the Expo Bare Workflow Migration We run a live, production dating application (iOS + Android, thousands of real users) and are migrating it from the React Native CLI setup to the Expo Bare Workflow - to unlock EAS Build/Submit, cleaner native configuration via config plugins, and code reuse across multiple app tenants. Required Skills & Experience (must-have) 1. SME-level depth in modern React Native - you can explain and have shipped with the New Architecture (Fabric / TurboModules / JSI), Hermes, and current Expo/EAS tooling. 2. Proven, hands-on experience migrating a React Native CLI app to the Expo Bare Workflow - please cite a specific project. (Top screening criterion.) 3. Deep expertise with EAS Build/Submit and Expo config plugins (writing custom plugins, not just consuming them). 4. Strong TypeScript in React Native. 5. Production experience with native modules: WebRTC (real-time video/audio), Firebase (Auth, FCM push incl. cold-start deep links, Crashlytics), and In-App Purchases (react-native-iap, incl. the Nitro/v15 vs v14 landscape). 6. Comfortable directly in iOS/ (Swift, Podfile, entitlements) and Android/ (Kotlin, Gradle, manifest) native layers. 7. Disciplined unit testing (Jest + RN Testing Library). 8. Experience shipping to App Store and Google Play — signing, provisioning, store compliance. 9. Communicates like an expert: clear written English, justifies decisions with facts and trade-offs, and documents patterns for a team to maintain. 10. AI-assisted engineering workflow (Claude Code) / ADRs. Nice-to-Have 1. Multi-tenant / white-label React Native architecture. 2. Mobile security depth (OWASP MASVS, secrets management, secure storage). 3. Experience leading RN version upgrades and Reanimated v4 + worklets edge cases. Deliverables (first project) 1. All remaining screens migrated, each with passing unit tests. 2. Subscription/IAP flow live and validated on both platforms. 3. WebRTC calling, FCM push (foreground/background/cold-start), and Firebase services verified end-to-end on physical devices. 4. Working EAS production build & submit pipeline with proper release signing. 5. Secrets migrated to EAS env/secrets; no hardcoded credentials in the repo. 6. A handoff/SME document covering architecture, config-plugin setup, and maintenance patterns. 7. Resolve production Firebase Crashlytics issues after deployment to the App Store and Google Play. 8. Remediate security vulnerabilities identified by automated scanners and Claude Code audits. We prioritize open and clear communication as well as project transparency. Please note that all meetings are recorded; candidates must have a high-quality headset, a high-quality webcam, and a reliable, high-speed internet connection. Additionally, use of the Upwork Time Tracker with screen captures is required for all logged hours.