Freelancer Senior Mobile Engineer (React Native, Expo, TypeScript) m/w/d

About This Opportunity

We are representing a confidential SaaS organization serving over 22,000 business customers across German-speaking markets. Our client is actively developing their mobile presence and needs a senior freelance engineer to shape the technical direction of their iOS and Android applications. This is a remote-first engagement with significant architectural responsibility.

The mobile application is built on React Native, Expo, and TypeScript, with core authentication and document management features already in place. You'll drive the next phase of development, working closely with product and backend teams to deliver reliable, performant features for business users on the go.

Responsibilities

• Develop and extend the mobile application using React Native, Expo, and TypeScript for both iOS and Android platforms
• Translate business requirements around documents and workflows into intuitive mobile experiences and high-quality native interfaces
• Evolve the application architecture with maintainable patterns for navigation, reusable components, forms, and data access
• Integrate REST APIs with typed interfaces, implementing robust data management including caching, loading states, and error handling
• Work at the intersection of mobile and backend; extend REST API endpoints using PHP and Symfony when new mobile features require backend support
• Implement secure authentication, session management, and careful handling of sensitive business and customer data
• Optimize performance across varying network conditions, app lifecycle events, and device capabilities while ensuring accessibility and internationalization
• Write automated tests and validate behavior across simulators and physical devices; contribute to build, release, and monitoring processes through App Store publication
• Challenge requirements constructively, propose solutions, and shepherd features from concept through release and iteration
• Leverage AI tools like Claude Code in daily development while taking full responsibility for output quality, clarity, and correctness

Current stack: React Native, Expo, Expo Router, TypeScript, TanStack Query, TanStack Form, Zod, NativeWind, Jest, React Native Testing Library. Backend: PHP, Symfony REST API.

What We're Looking For

• Senior-level expertise with TypeScript, React Native, and Expo, with mobile applications taken through full release cycles
• Deep understanding of React fundamentals, component architecture, state management, and asynchronous data flows
• Strong knowledge of iOS and Android platform differences with systematic approaches to performance issues, platform-specific bugs, and debugging
• Confidence integrating REST APIs with attention to contracts, authentication, validation, and error handling
• Ideally, working knowledge of PHP and Symfony to understand existing endpoints, diagnose issues across the stack, and extend APIs independently
• Commitment to automated testing, clear technical decisions, and maintainable code as standard practice
• Independent, pragmatic work style with clear communication and focus on end-user value
• Fluent German and good English language skills
• Freelance availability with no conflicts of interest

Bonus experience: EAS, native modules in Swift or Kotlin, App Store publication processes, published apps in production, open-source contributions, or public experiments demonstrating technical depth.

If you don't check every box but are an exceptionally strong engineer with a track record of ownership and delivery, we still want to hear from you. Show us what you've built.

How We Work With You

Get A Job.ai is a recruiting partner working on behalf of our client. When you apply through our platform, one of our technical recruiters will review your background and portfolio, then conduct an initial screen. If there's a strong match, we'll submit your profile to the client for their review and interview process.

Please do not contact the client directly. All communication and coordination will flow through Get A Job.ai to ensure a smooth, professional process for everyone involved.

This is a remote-first freelance engagement with flexibility around location within Germany. The role offers the opportunity to influence technical strategy in an early-stage mobile product with real business impact.

Pay

Compensation details will be discussed during the screening process based on experience level and project scope.

Equal Opportunity: Get A Job.ai is committed to inclusive hiring practices. We evaluate all candidates based on qualifications and merit, and we encourage applications from people of all backgrounds.