Senior mobile development for DACH companies that want to grow fast — speed and stability, without the tech debt.
Three projects, told briefly: from problem to measurable outcome. The throughline — ship faster without the architecture paying for it.
01 · ON AG · AI · E-commerce
02 · Purelei · E-commerce
03 · BRACK.CH · E-commerce · Retail
A clear, repeatable process makes speed predictable and architecture resilient. AI-native means modern tooling compresses the routine work — the judgement stays human.
Sharpen goal, scope and success criteria together. A clear spec, not a vague wishlist.
Modular architecture from day one. AI-assisted routines speed things up; reviews keep quality high.
Automated tests, performance and crash monitoring. Evidence over gut feel.
CI/CD all the way to the stores. Clean handover, documented and maintainable.
Flutter and Dart at the core, plus a toolchain that automates the repeatable. Not "AI builds your app" — just less friction per release.
Flutter
Dart
Riverpod
Firebase Freezed
Fastlane
Sentry
SvelteKit
React
Tailwind CSS
Vite
NestJS
FastAPI
Prisma
PostgreSQL
Redis
Strapi
Docker
GitHub Actions
Playwright
Claude Code
OpenSpecWonderful, professional collaboration! K. laid the foundation for our entire mobile app development. Highly recommended!!
Andre Gröschel TrippleACode GmbHProfessional, results-oriented, always friendly collaboration. To be recommended without reservation. Thank you, K.!
Timo Mugele Framegrabber GmbHK. won us over with clear communication and full commitment. We can only recommend working with him.
Tim Schröder MassiveMiniTeam GmbHKhalid has both, self-organization and autodidactic knowledge and abilities, thus he is stepping out, compared to regular flutter developers!
Max Arbeiter SnapNext GmbHK. was a very valued colleague in my department. He was very reliable and always happy to support others in the team.
Andreas Partenhauser MediaMarktSaturn Technology GmbHWonderful, professional collaboration! K. laid the foundation for our entire mobile app development. Highly recommended!!
Andre Gröschel TrippleACode GmbHProfessional, results-oriented, always friendly collaboration. To be recommended without reservation. Thank you, K.!
Timo Mugele Framegrabber GmbHK. won us over with clear communication and full commitment. We can only recommend working with him.
Tim Schröder MassiveMiniTeam GmbHKhalid has both, self-organization and autodidactic knowledge and abilities, thus he is stepping out, compared to regular flutter developers!
Max Arbeiter SnapNext GmbHK. was a very valued colleague in my department. He was very reliable and always happy to support others in the team.
Andreas Partenhauser MediaMarktSaturn Technology GmbHFrom a no-strings intro call to a long-term partnership — clearly scoped, so both sides quickly know if it fits.
We clarify your idea, feasibility and a realistic timeframe.
Focused help on performance, crashes, migration or an MVP in weeks.
A reliable mobile partner for roadmap, maintenance and continuous releases.
A Claude Code skill checks Flutter code for GDPR compliance before every merge. What it found — and what I did about it.
An 8-month serverless infrastructure fight, 5 months of silence, and a 3-week rewrite with git logs to show for it.
A ~30-line, dependency-free technique for programmatically restarting a Flutter app by rebuilding the entire widget tree.
I'm a freelance senior mobile developer in Berlin and I've been building apps for over seven years — most of that with Flutter.
My focus is a rare combination: ship fast while leaving behind architecture that scales with you. The exact spot where speed usually creates tech debt is where I like to work most.
Depending on scope, in a few weeks rather than months. In the intro call we scope it realistically — honest beats over-promised.
No. It describes how I work: modern tooling compresses routine work so I deliver faster. The architecture and quality decisions stay human.
Yes. Performance issues, high crash rates, migration to Flutter or stabilising a grown app are among the most common requests.
German or English — both fluent. Usually German with DACH companies, English with international teams.
Cleanly documented, tested and maintainable. The goal is that your team can keep building independently afterwards — no lock-in to me.
A 30-minute intro call is free and no-obligation — and you'll know afterwards if it's a fit.