My portfolio

I’ve worked across a range of industries from aviation to real estate.
Some of my work isn’t public, but here is a selection of projects I can talk about.


Menstrual health app

Clue is a leading femtech app with over 12 million users around the world. I helped their iOS team improve the app’s architecture while building major new features – most notably Clue Birth Control, an FDA-cleared digital contraceptive.


  • Massive global userbase (localized for 15 languages)
  • Reactive, testable MVVM+C architecture
  • Automated signing & distribution process
iOS / watchOS Swift Objective-C Kotlin


Investment app

I helped Donut build their iOS app from scratch, all the way until App Store launch. Our tight-knit team was able to iterate quickly based on user research, while keeping the solid foundation that users expect from a financial app.


  • Banking integration
  • Composite animations
  • Rich, flexible design system
React Native GraphQL TypeScript

Jumu weltweit

Youth music contest hub

I built a web application and mobile apps for “Jugend musiziert” contests in 16 countries to replace heaps of paper forms and printed schedules, and help young people connect across borders through music.


  • Fully open-source
  • Drag-and-drop scheduler
  • Dynamic PDF generation
  • Handling of complex domain model
Phoenix GraphQL React Native


Urban activity app

Available on iOS and Android, FriendHood allowed people in Berlin to organize activities together. As their CTO, I planned the tech architecture, wrote most of the app and server-side code, and participated in the UX and visual design process.


  • Polished app UI & UX
  • Design informed by rapid prototyping
  • Cross-platform codebase
  • Real-time chat powered by GraphQL
React Native GraphQL Phoenix