Senior Software Engineer

Migrating existing native mobile apps to a hybrid platform (React Native)

• Analyzed and created a migration plan
• Reviewed the existing implementation
• Migrated a tracking and user engagement system
• Technologies used: React Native · Android · iOS · Braze SDK · Jira · Confluence · GitHub

Built a company website with Next.js

• Multi-language support
• Contact form with reCaptcha v3
• Theme switching
• Technologies used: Next.js 14 · TypeScript · shadcn · reCaptcha v3 · Tailwind CSS Backend: Azure backend development

Built a technology demonstrator

• QR scanner app with Kotlin
• Set up CI/CD in GitLab
• Automated Android security checks within the CI/CD
• Automated deployment to Firebase App Distribution for app testers
• Automated deployment to Google Play Store (Internal, Alpha, Beta, Production)
• Set up Git hooks for pre-commit checks like Detekt and ktlint for code quality and formatting
• Technologies used: Android · Kotlin · Jetpack Compose · GitLab CI/CD · MobSF (App Security) · Firebase App Distribution · Fastlane · Docker · Detekt · ktlint · Jira · Confluence · GitHub

I was one of the developers for the Barmer app and took over the project after several freelancers left it in a “challenging” state.

• Lead developer for the core application
• Took over and managed the profile management module
• Proactively defined and enforced code conventions for React Native and TypeScript, significantly improving quality
• Developed and implemented a simplified startup process for the entire app in React Native, Android, iOS, and four specialized modules
• Participated in architecture discussions and advised architects
• Provided technical support and acted as contact for third-party companies (IBM iX, Adesso, BARMER)
• Designed and implemented dynamic module integration
• Mentored and supported multiple developers
• Handled feature tickets and actively participated in organizational matters
• Refactored inefficient code
• Conducted performance analysis and developed solution concepts and metrics for efficient screen rendering on different devices
• Served as an ambassador for the IBM iX (BARMER) design system, in direct contact with the lead developer
• Developed interfaces for native code components
• Technologies used: React Native · React · React Native Web · TypeScript · JavaScript · TeamCity (CI/CD) · Jest (test framework) · Appium · Firebase (Crashlytics · Push · Remote Config · etc.) · REST · Redux · Monorepo management · BARMER Design System · Scrum · GitLab · Jira · Confluence · Sentry · Bitbucket · QR scanner

Assigned to DaimlerBuses

• Planned and designed video and camera systems for coaches

Founded a postcard mailing app

• Founder and developer of iPostcard.org
• Created a concept for a postcard mailing app
• Android app development end-to-end
• iOS app development end-to-end
• Backend development within a cloud solution (Microsoft Azure)
• Developed a management system for automated generation of print documents
• Developed a mobile management system for order management
• Postcard and greeting card printing service using mobile software applications
• Developed mobile applications on Android end-to-end & iOS (Swift) as well as backend development (C# & MSSQL)
• Marketing, support, etc.
• Used technologies: Android · iOS · Java · Swift · Microsoft Azure · REST · Backend · WebApp · Frontend WPF · C# · Firebase (Authentication · Push · Remote Config) · Entity Framework · Google Ads · Apple Search Ads · MSSQL · .NET and many more.

Development work on the central train control unit (ATP-CU)

• Developed concept for the startup procedure of the Automatic Train Protection Control Unit (SIL4) – software based on Linux and FreeBSD real-time systems (ARM and PowerPC)
• Modified existing source code to fix issues and add features (C / C++)
• Analysis and implementation of "NCR" and "CR"
• Created Debian installation packages
• Implemented safety integrity requirements, e.g. CRC checks during the startup procedure of the dual computer
• Implemented startup scripts (Linux/FreeBSD)
• Verified test reports
• Development according to V-model
• Developed safety-critical and non-safety-critical software (SIL 4)
• Developed features for the European Train Control System (ATP-CU)
• Used technologies: FreeBSD · Linux · C · C++ · DOORS · ETCS · EBI Cab 2000 · ATP-CU · BASH · Shell scripts