Portfolio
React Native, TypeScript, and full-stack delivery for web and mobile products
I build mobile apps with React Native and TypeScript (including wikifolio and my own Budget for Nomads release) plus Next.js web apps, cloud backends, and AWS where it fits. Focus areas are clear UX, testable architecture, CI/CD, and close work with product, design, and backend. A strong fit for SMEs and teams that want senior-level work with flexible freelance collaboration instead of an agency retainer.
Bremen · Remote · DACH & EU
Services
Web, mobile, and full-stack: from MVP to production-ready delivery.
Rates
Indicative rates (not a fixed quote): 60 € per hour, 240 € per day (4 hours), 4.800 € per month at 80 hours. Invoices are issued at the start of the following month for the prior month.
Next.js apps with APIs, auth, and SEO-ready delivery from MVP to production.
React Native and Expo for iOS and Android with store releases and EAS pipelines.
Node.js, PostgreSQL, Prisma, Supabase, and AWS — shaped for your team and budget.
Tests, CI/CD, and pragmatic security — real engineering — not vibe coding.
Work
Selected work — shipping, maintainable systems for web and mobile.
2022-2024 · Freelance · design & build
React Native and Expo travel budgeting app: per-trip spending, daily rollups, categories, and multi-currency handling with sync between online and offline use. Built end to end as a freelance flagship (TravelCost Native) with Firebase, Zustand, and UX focused on long-term travelers.
2024-2025 · Mobile app developer
Cross-platform React Native app for iOS and Android: extending a trading and community product with a native rich-text editor for comments, animated tables and charts, Branch.io deep and native linking, automated tests (Jest, Maestro), and CI/CD for releases, alongside backend, design, and product partners.
2026 · Design & build
Public freelance portfolio as a static Next.js export with Tailwind CSS v4, localized routes, and JSON-driven projects and skills. Shipped with Docker and Caddy on a Hetzner VM with performance and clear SEO metadata in mind.
Next.js web app for German freelancer invoicing: drafts, finalization, PDF storage on Vercel Blob, email delivery with Resend, Stripe Checkout for payments, and reminder jobs via cron. Built for a clear path from draft to paid.
Expo app with a Mapbox web view and AWS backend: trip GeoJSON is rendered to video with Remotion on Lambda, stored in S3, and downloaded to device or web. The stack includes CDK, Cognito, and Amplify for an end-to-end cloud pipeline.
Expo Router water intake MVP: daily goal, quick logging with AsyncStorage, an SVG progress ring, and repeating local notifications via expo-notifications. Focused on simple use and a clear daily view.
Cross-platform habit app with charts (react-native-chart-kit), Expo Router, Reanimated, and EAS builds. Structured for recurring habits and visual feedback over time.
Expo finance-style demo with Firebase, Zustand, and React Native Paper: card stacks with gestures and Reanimated, MMKV persistence, and Jest with Testing Library. A playful UI for quote or watchlist style content.
Multi-tenant SaaS starter in a Turborepo: Next.js App Router, Supabase, billing via Stripe or Lemon Squeezy, i18n, feature packages, and Playwright E2E. A base for SaaS products with teams, auth, and billing.
2025-present
Large Expo app on AWS Amplify with AppSync and GraphQL, many Lambda functions, and EAS CI for TestFlight and production. Quality with Jest and Maestro, analytics integrations, and continuous releases.
Mobile card battle prototype with Expo, Firebase Auth and Firestore, Cloud Functions for server logic, and Zustand for client state. Structured for realtime matches and extensible card decks.
Twitch-inspired Expo MVP with a stream feed, categories, and native video playback using Expo Video plus React Navigation. Built as a technical playground for video lists and navigation.
2019-2020 · Mobile app developer
Xamarin and .NET app with SQLite for the Freiburg Institute of Music Medicine: built together with clinicians, physics, and design, with full on-device responsibility. Available on the App Store as Stage:Cool for reference and inspiration.
Stack
Mobile-first: React Native & Expo, iOS/Android releases, plus web and backend.
React Native apps for iOS & Android with Expo/TypeScript — including an app-store-ready release process (EAS Build/Submit) and stable updates.
Web UIs, landing pages, and dashboards as a complement to the app — fast, responsive, accessible, with i18n and a solid performance baseline.
APIs, auth, and data models for mobile apps — with PostgreSQL/Prisma or Supabase, plus CI/CD and automated tests for reliable releases.
Additional project experience — useful depending on legacy systems and stack constraints.
Contact
Pick a time directly. I will reply with concrete next steps. English enquiries are welcome end to end when you prefer.