I've spent 8+ years building production systems in Kotlin, Java and TypeScript, from payment gateways to video streaming. Lately I've built five apps of my own, fast, with AI. I'm based in Salzburg and work remotely in English, Spanish or German.
Kotlin and Java services that handle money and traffic: APIs, gateways, event streams.
Web and mobile products built end to end, then improved based on what users actually do.
The part I enjoy most: understanding what clients need, and helping teammates grow.
Five apps from 2026, each designed, built and deployed by me with AI-assisted development. The code is private, but I'm happy to walk you through any of it on a call.
Learning, built like a climb.
Every subject becomes a tower of floors with AI-generated lessons and a boss fight at the top. It includes a content back-office, an Android build and deploys on every merge.
A workout log that works without signal.
It's offline-first: workouts save to the phone and sync later. Quick-add like row 3x10 55, and it suggests your next weights.
Demo video coming soon
Plant care that knows the weather.
It tracks your plants alongside local weather, and you can ask the AI questions about each plant.
Demo video coming soon
Thermomix recipes from what's in your fridge.
It generates step-by-step recipes with exact machine settings for your model, and costs $0 a month to run.
Demo video coming soon
A nap tracker for twins that measures the parent's rest.
Other trackers follow each baby. Tandem tracks "together time": the minutes each day when both twins sleep at once. It works offline and is shared across the household.
Demo video coming soon
Some apps are published under my studio, Stone Ladder. Thermomix® is a trademark of Vorwerk; Stirwise is independent and not affiliated with Vorwerk.
Kotlin/Micronaut services and Compose Multiplatform back-office tools for One+, a Swiss video-streaming platform.
Owned the Java/Vert.x gateway and Angular portals for a fuel payment system used at thousands of stations in five European countries. Led the 3-person operations team, and interviewed and mentored junior developers.
Payment checkout services for Latin America's largest e-commerce platform, serving 25M+ active users.
IVR applications for customer-service systems. Ran workshops and knowledge-transfer sessions for client teams.
I break work into small pieces and post a short update every day, so you always know where things stand.
I use AI to move fast, and I understand and stand behind everything I ship.
I'd rather spend ten minutes asking what you need than a week building the wrong thing.
Have a contract, a role or a product idea? Send me a few lines and I'll reply within a day.