Senior Mobile Engineer - React Native, Expo, TypeScript

Project overview

You are deeply proficient in TypeScript, React Native, and Expo, understand the specifics of mobile applications, and want to significantly shape a product in its early development phase. Ideally, you also have knowledge of PHP and Symfony to help shape functions on our REST API side.

Responsibilities

You will continue development for iOS and Android based on React Native, Expo, and TypeScript. A technical foundation with login, dashboard, and document overviews is already in place. You will build upon this and shape the next steps together with the team. You will translate requirements related to invoices and documents into understandable mobile workflows and high-quality native interfaces. You will further develop the app architecture and create maintainable structures for navigation, reusable components, forms, and data access.

You will connect our REST API and ensure reliable data management: from typed interfaces and validation to caching, loading states, and error handling. You will work at the interface between app and backend. If necessary, you will extend our REST API based on PHP and Symfony so that new mobile functions can be implemented end-to-end. You will work on secure authentication, session management, and the careful handling of sensitive customer and business data. You will keep an eye on performance and platform specifics – even with changing network connections, app switching, and different devices.

Accessibility and multilingualism are part of your product quality. You will secure changes with automated tests and check behavior on simulators and real devices. You will help shape build, release, and monitoring processes up to publication in the app stores. You will question requirements, contribute your own solution proposals, and accompany functions from idea to publication and further development. You will intensively use AI tools like Claude Code in daily development and take responsibility for the quality, clarity, and correctness of the results.

Our mobile stack includes React Native, Expo, Expo Router, and TypeScript. Additionally, TanStack Query and TanStack Form, Zod, and NativeWind. For testing, we rely on Jest and React Native Testing Library. Our existing platform and REST API are based on PHP and Symfony.

Requirements

You don't have to know every library yet. The crucial thing is that you understand your stack, make good technical decisions, and teach yourself new topics independently. You have profound, senior-level experience with TypeScript, React Native, and Expo, and have accompanied mobile applications beyond pure implementation up to release. You understand React, component architecture, state management, and asynchronous data flows, and can structure complex contexts understandably. You know the specifics of iOS and Android and systematically approach performance issues, platform errors, and debugging.

You are confident in connecting REST APIs and understand API contracts, authentication, validation, and error handling. Ideally, you also have knowledge of PHP and Symfony. You can understand existing API endpoints, analyze errors between app and backend, and independently extend interfaces. Automated tests, traceable technical decisions, and maintainable code are part of your daily development routine. You work independently and pragmatically, communicate clearly, and keep the benefit for our customers in mind. You speak fluent German and have good English skills.

Additional plus points include experience with EAS, native modules in Swift or Kotlin, and app store releases and mobile release processes. Your own published apps, open-source contributions, or public experiments on GitHub are also welcome.

Project details

• Start: flexible
• Location: DE
• Languages: German