Introduction
Filen is an independent technology company based in Germany. We develop and operate a secure cloud service that enables true privacy. Since 2020, Filen has stood for zero-knowledge encryption, top-level data protection, and transparent software development without backdoors.
Our mission is to give people full control over their data. Every file stored with Filen is fully end-to-end encrypted and can only be decrypted by the user. The result is a cloud that is secure, private, and easy to use.
To further improve our mobile user experience, we’re looking for a dedicated Mobile App Developer (m/f/d) to maintain, optimize, and actively develop our iOS and Android apps.
About the App
Our mobile app is technically sophisticated and much more than just a frontend. It includes extensive business logic, encryption, performance optimization, and a complex architecture. We’re looking for someone who understands the entire development process, enjoys working deep in the codebase, and takes pride in building well-structured, high-performance systems.
🧠 Who we’re looking for
You're a mobile developer who knows your way around cross-platform apps, native modules, and modern dev stacks? Perfect.
What you’ll do:
- Further develop, maintain, and optimize our mobile apps for iOS and Android
- Implement new features, fix technical issues, and improve performance
- Take ownership of projects and features from concept to release
- Plan and execute your tasks independently
- Actively contribute to product decisions and technical architecture
✅ Requirements (Tech)
- Strong knowledge of React, especially React Native, including React rendering, the Rules of React, and the React Compiler (required)
- Very good knowledge of TypeScript
- Solid experience with Node.js and Expo (not Expo Go, but Expo DevClient)
- Knowledge of Swift or Objective-C for iOS
- Knowledge of Kotlin or Java for Android
- Interest in secure software architecture and high-performance mobile applications
- Ability to work independently after a standard onboarding period
We're looking for someone who’s comfortable working across the full stack of our mobile codebase – both cross-platform and native.
You don’t need to be an expert in all of these areas. If you’re motivated, have hands-on experience with more complex React-based apps, and learn quickly, we’ll support you in deepening your skills and mastering new technologies.
✅ Requirements (Personal)
Aside from the technical requirements, we also have a few for you personally:
- You speak and understand fluent English OR German.
- You are legally allowed to work in the EU and ideally live there.
- You are able to work very well independently and are confident enough in your work that no one needs to constantly look over your shoulder.
- You believe that after a normal onboarding period, you can get started right away.
- You would like to work part-time or full-time.
🎁 What you’ll get
- Completely flexible working hours – you decide when and how you work
- A true work–life balance that adapts to you, not the other way around
- The option to work fully remote
- A young, relaxed team that values collaboration and trust
- Real responsibility and room for your own ideas
- Flat hierarchies and an open, respectful feedback culture
- A secure product used by thousands of people every day
- Time and support for your personal and professional growth
- Snacks and drinks available for everyone working on-site
- A motivated, friendly team focused on quality, security, and reliability
✉️ How to apply
We made it super easy:
👉 Use our Smart Application Tool
No cover letter needed. Just a few clicks and you're in.
Any questions? Get in touch anytime - via email, social media, or support.
Looking forward to hearing from you!
– Team Filen
