Freelance Senior Mobile Engineer (React Native, Expo, TypeScript)

Stack

Responsibilities

• ▹Continue developing easybill-mobile on React Native, Expo and TypeScript for iOS and Android, building on the existing technical foundation (login, dashboard, document overviews)
• ▹Translate requirements around invoices and documents into clear mobile flows and high-quality native interfaces
• ▹Evolve the app architecture, creating maintainable structures for navigation, reusable components, forms and data access
• ▹Integrate the REST API and ensure reliable data management: typed interfaces, validation, caching, loading states and error handling
• ▹Work at the interface between app and backend; extend the PHP/Symfony-based REST API where needed so new mobile features can be implemented end to end
• ▹Work on secure authentication, session management and careful handling of sensitive customer and business data
• ▹Keep performance and platform specifics in mind across changing network connections, app switching and different devices
• ▹Treat accessibility and multilingual support as part of product quality
• ▹Secure changes with automated tests and verify behavior on simulators and real devices
• ▹Help shape build, release and monitoring processes through to App Store publication
• ▹Question requirements, bring your own solution proposals, and follow features from idea through release and further development
• ▹Make intensive use of AI tools such as Claude Code in daily development, taking responsibility for the quality, clarity and correctness of the results

Requirements

• ▹Working as a freelancer, deeply experienced in TypeScript, React Native and Expo
• ▹Understands the specifics of mobile applications and wants to shape a product in an early development stage
• ▹You don't need to know every library already, what matters is understanding your stack, making good technical decisions, and getting up to speed independently on new topics
• ▹Solid, senior-level experience with TypeScript, React Native and Expo, having accompanied mobile applications beyond pure implementation through to release
• ▹Understands React, component architecture and state management

Nice to have

• ▹Knowledge of PHP and Symfony, to also help shape features on the REST API side

About the company

More than 22,000 businesses rely on easybill; the company makes sure invoicing, processes and integrations run smoothly in day-to-day work. With easybill-mobile, they are bringing core platform functionality to iOS and Android.