Senior Product Engineer
I turn unclear product ideas into software that holds up in practice.
About
I’m based in Berlin and have worked across backend systems, full-stack product interfaces and infrastructure. I like staying close to both the product decisions and the implementation.
Right now, I’m building Phemilo, a native strength-training product for iPhone and Apple Watch. Alongside it, I work on retrieval, AI evaluation, internal tools and integrations.
01Work and notes
One product I build and operate, followed by two notes on the technical questions behind my recent AI work.
Independent product · iOS · AI fitness
A native iOS and watchOS strength-training product for progressive overload, training history and AI-supported coaching. I designed, built and released it independently.
I own the native apps, backend, subscriptions and release. The AI coaching work includes workout-history analysis, plan generation, retrieval, tracing and evaluation.
02
Experience note · Retrieval and citations
What I learned about keeping document answers grounded, traceable and willing to stop when the evidence is not enough.
Problems I worked through
03
Experience note · AI evaluation and observability
The evaluation habits I use to make prompt, model and tool changes without relying on a convincing demo and intuition alone.
Problems I worked through
02How I work
I narrow the problem first: who needs what, what can wait and what the first version has to prove.
Architecture matters, but so do tests, deployment, monitoring and the next iteration. I prefer to stay close to all of them.
I keep retrieval, prompts, tool calls and evaluation observable so failures become cases to fix rather than anecdotes.
03Experience
06.2025—NOW
Senior Product Engineer
Building Phemilo’s native apps and AI coaching workflows, including workout-history analysis, plan generation, retrieval and evaluation.
11.2022—06.2025
Backend Developer (Full Stack)
Optimised Symfony and Node.js services, improved API response times by 35% and built an Angular activity log for enterprise user actions.
11.2020—10.2022
Software Developer
Led work on Angular modules for a healthcare platform, expanded unit and integration tests and supported reviews, pairing and junior developers.
03.2020—11.2020
Full-Stack Developer
Built Visticle, a multi-tenant Laravel commerce platform that synchronised products with Amazon, Zalando and other sales channels.
02.2019—03.2020
Freelance Developer
Prototyped a multi-tenant commerce platform, built a Flutter application and handled backend migrations and maintenance for clients.
06.2018—02.2019
Junior Software Engineer
Worked on a large e-commerce platform built with CakePHP and AWS-based microservices.
04Contact
I’m open to permanent roles and focused freelance projects.
For teams Senior product, backend or full-stack engineering roles.
For projects Product builds, integrations and AI evaluation work.