Headless & API-first web
Fast frontends that search engines and AI can actually read. Astro, React/Next or SAP Commerce Cloud, depending on the job. Rendered on the server, not a sluggish client app.
Leaster · IT engineering
Good IT goes unnoticed. It just works.
I build websites, cloud setups and automation, and I look after the part nobody sees afterwards. Keeping it secure and stopping it from falling over in production. This page is the first work sample, server-rendered, fast, no cookie banner.
- 0 KB JS by default
- Native light/dark mode
- Structured data & llms.txt
- AI-native · no vibe coding
Capabilities
Five things I can do and have already shipped.
Not a wish list. Every point has working software behind it.
Cloud, identity & zero trust
Azure environments, EntraID and Azure AD B2C, zero trust and ringfencing. I’ve run whole provider landscapes in a corporate setting, not just clicked together a single tenant.
Automation & AI integration
Python that clears out the busywork, things like data sync, ETL and pipelines. I had LLMs in production before anyone said “GenAI”. No toy project. It saved real work from day one.
DevSecOps & self-hosting
All the invisible operations: deployment pipelines, containers, reverse proxies, security scans, DNS. Portainer, Plesk, Nginx Proxy Manager, usually on my own hardware. The stuff you only notice when it’s down.
Cross-platform & mobile
Apps for Android, iOS and desktop from one source, with offline sync and a clean link to your own API. Kotlin, .NET MAUI, WPF.
Work
A few things I’ve built.
Where I’m allowed to name names, I do. Where I’m not, the solution has to speak for itself.
diebema.de — IT operations & headless relaunch
I run the entire IT of a finance and real-estate advisory firm, and I’m moving its website from WordPress to a headless Next.js/TypeScript setup on the side.
Digital platform for a nationwide community
A CMS core I extended with my own Python/REST ecosystem. Native and cross-platform apps, automated newsletter and social posting, plus AI that reads event data and writes it straight into ticketing. Geodata and lifecycle automation came later.
Multi-tenant headless SaaS
A multi-tenant SaaS platform on React and Python, containerized and API-first. I handle the database, the backend and the operations myself. I’ll name it once it’s live.
Identity & web tools in a corporate environment
Internal tools behind single sign-on. Azure AD B2C integrations, claims and SAML, plus a few production web apps. Nothing public to show. Here it counts as capability, not a showcase.
sandys-beestore.de — webshop & IT operations
Built the online shop and kept the IT side running ever since. Hosting, updates, all the bits around it. The owner sells, I make sure the shop never stalls on the technical side.
Smaller sites, the same hand for years
Built and still maintained, without infrastructure or hosting. hundeschule-frankenalb.de and bavarian-starlights.de are part of it, along with zenn-pflege.de, which I built years ago for a care service. Small clients, a long line.
mtg_benchmark
A public Python project. Work you can read in the source instead of taking my word for it.
Tools
Small tools, free, no strings.
Self-built, free, no tracking, no sign-up. Just use them.
live
QR code generator ↗
QR codes in your own colors, as SVG or PNG, plus an open API. Free and tracking-free.
liveBusiness-card creator ↗
A digital business card as a vCard QR on a phone wallpaper. Shareable, printable, no account.
liveSite-Check ↗
Checks a website for SEO, AI readiness, privacy and performance — in seconds, with an open API. No tracking, no sign-up.
Origins
Started in 1999. Aged 16, writing HTML by hand.
My first keyboard still had a five-pin DIN plug, the monitor glowed black-and-green, and the modem had to whistle its way online before a page would even load. That’s when I started building websites. By hand, evening after evening, because it had me hooked.
Since then it’s grown into countless projects on almost as many systems: WordPress, phpBB3, Joomla, later headless and API-first. Changing clients, changing tech, and every time whatever the law happened to be. Most of it on the side and unpaid, without much to show for it on paper. Because I could, and, honestly, because I’m a decent sort. And a little for the good karma.
More than 25 years of tinkering eventually turned into a craft. What’s on this page didn’t appear overnight. It’s the sum of a great many evenings.
- Five-pin DIN plug
- Windows 3.0
- 56k modem
- Black-and-green monitor
Approach
How I work.
No slide decks, no agency speak. I take a project the whole way, from the first architecture to day-to-day operations, and I do it myself instead of farming it out across three vendors.
I didn’t come up through computer science. For nearly 20 years I led teams in healthcare, up to about 100 people towards the end. In 2020 I started over completely and retrained. You can still tell in the way I work. I look at the people who’ll have to live with a system first, and the tech second.
Whatever can be automated, I automate. Whatever needs protecting goes behind zero trust. Sounds dry, and it is. That’s why it holds up.
I built this site with Claude Code. AI-assisted, but no vibe coding. There are clear rules and a clean architecture, and every decision is written down. That’s what good software looks like to me in 2026, and the best proof is that you’re looking at it.
Questions
Quick answers.
What is Leaster?
My personal label for everything I build outside the day job: websites, self-hosting, automation and a few free tools. Not a company, not an agency — one person.
Are the tools really free?
Yes, all three of them: the QR generator, the site check and the open API cost 0 € — no signup, no tracking, no catch. They run on my own infrastructure.
Why no cookie banner?
Because I keep the measurement lean. Reach is tracked with self-hosted Matomo — cookieless and with a truncated IP, nothing goes to third parties. There is no consent-requiring cookie, so there is no banner. If you still don’t want to be counted, one click in the privacy policy opts you out.
Do you take requests?
This site sells nothing — but talking costs nothing either. If you have a project in mind, reach out on LinkedIn or by mail.
Contact
Say hello.
This site isn’t selling anything. It’s just here so the work can speak for itself. If you fancy a chat, LinkedIn’s the easiest way.