Interim Mobile Application Developer - React Native / Expo

• taken existing React Native applications through SDK upgrades,
• security remediation, build fixes and App Store / Google Play re-submission
• Fully remote but needs to be UK based

This is a short-term Mobile Application Recovery / Modernisation assignment rather than a conventional "App Developer" role.I urgently need someone who has actually taken existing React Native applications through SDK upgrades, security remediation, build fixes, and App Store / Google Play re-submissionOur client, a UK business within the construction industry, has a customer-facing mobile application for iOS and Android that needs urgent technical recovery. Built with React Native, Expo, and ASP.NET Core, the app provides customers with smart telemetry data from units-energy consumption, CO2 emissions, and asset tracking-but is currently unavailable on both app stores due to outdated SDKs and unresolved compatibility issues. This is a temporary role offering an initial 3-10 day assignment to stabilise the application and return it to production, with the opportunity for ongoing monthly support thereafter. The position is remote, and the successful candidate will take full ownership of the existing codebase, identify root causes, and manage the release process to both stores.

• Take ownership of an existing React Native application, diagnose critical issues, and restore it to both the Apple App Store and Google Play Store
• Initial 3-10 day assignment with potential for ongoing 1 day per month maintenance and support
• Predominantly remote, with occasional on-site meetings if required

Preferred Requirements

• Proven expertise in React Native and Expo, with hands-on experience updating SDKs and resolving build and compatibility issues
• Strong track record of successfully taking existing mobile applications through Apple App Store and Google Play Store updates or re-submissions
• Solid understanding of iOS and Android development, including build configurations, certificates, signing, and deployment processes
• Experience with ASP.NET Core, Microsoft Azure, and REST API integration
• Comfortable debugging mobile applications, troubleshooting crashes, and managing the release and submission process end-to-end

Preferred Qualifications

• Demonstrable experience as a senior mobile or React Native developer with a portfolio of production applications
• Familiarity with App Store Connect, Google Play Console, and Expo EAS for deployment and release management
• Knowledge of mobile application security best practices and experience with Microsoft Entra ID or Azure AD B2C