Hi, I'm Stefan
Notes on data sovereignty, self-hosting, and the tools I actually use.
I'm a software engineer building AI-integrated systems for regulated European sectors. I write about where data should live, running my own infrastructure, and the everyday craft of the job.
Recent writing
Archive →Can You Actually Leave?
Exit cost is the sovereignty metric nobody prices -- and the privacy-respecting choice is not always the easy-to-leave choice.
The generation boundary
The model is a config key. The boundary behind it is the real commitment -- as code.
What "on-premises AI" actually means in 2026
Four tiers of 'on-premises', from EU-region cloud to your own rack, and where each breaks.
Why your AI pilot shouldn't leave the EU
'EU region' buys residency, not jurisdiction -- where data sits is not whose law applies.
Your tool catalogue is your data-flow specification
Notes on building a personal AI assistant over my Obsidian vault, and the architectural decision that makes a data-sovereignty story possible at all.
.NET CLI Commands I Actually Use
A practical guide from daily development experience
What I write about
Series →AI you're accountable for
Jurisdiction, on-premises models, agent harnesses, and what it takes to leave the hyperscalers.
My own stack, end to end
Self-hosting, Linux, NixOS, and the infrastructure behind my desk.
The day-job craft
Editors, CLIs, build systems, and keeping a .NET stack pleasant to work in.