Digital entrepreneur · Investor · Mentor — Berlin · AI · Health · Education
I build. Software, companies, and places where new things begin.
For thirty years I've been turning ideas into systems that hold up in everyday life — from the first line of code to a company of 300 people. Today my week, based in Berlin, belongs to my own products, investments, boards and mentoring. This is where I show what I'm working on: concrete, honest, and free of jargon.
If you're building something yourself: write me — early and unfinished is very welcome. The best conversations rarely start with a finished plan.
About
Thirty years of building — the short version.
I started in the nineties with code. Code turned into products, products into companies, companies into responsibility: built up, scaled, bought, sold, integrated. The most important lesson from all of it is unspectacular — good technology happens where someone thinks product, team and numbers together. And keeps at it.
What people bring to me
Build or buy, legacy or greenfield — and what the code can really do once you look inside.
What gets built and what deliberately doesn't — and how to tell early whether it holds.
Scaling paths, interfaces, technical debt — and the interest it charges.
Teams, responsibility, speed: structure follows decisions, not the other way around.
Technical, regulatory, entrepreneurial — assessed realistically instead of moderated away.
Who decides, who controls, who is liable — settled before it matters.
Compliance read as a design constraint — build it in early and you're faster later.
Cap table, valuation, roles: capital tied to work and responsibility.
The question behind all the others: who bears the consequences — and do they know?
Milestones
- Roles
- Founder, CTO, COO, CEO, board member, investor — from code to boardroom
- Scaling
- from 8 to 300+ people, from €2M to €100M+ in revenue
- Systems
- platforms serving billions of requests a day
- Ownership
- acquisitions, integrations, exit
Not theory. Built.
Craft
Judgment needs craft. Mine comes from three decades of building, marketing and leading — technology and marketing as one system, not two departments.
Technology
- Architecture & platforms — up to billions of requests a day
- Data, automation & decision systems
- AI systems & operating models
- Tech due diligence, build vs. buy
- Close to code since the nineties
Marketing & market
- Performance marketing & ad tech at scale
- CRM, lifecycle & data models
- SEO & visibility in AI search
- Positioning & pricing
- Brand with substance
Product & leadership
- Product strategy & prioritization
- Building teams: from 8 to 300+
- M&A: acquisition, integration, exit
- Boards & governance
Ventures
What I'm building right now.
On paper, this is probably what you'd call a serial entrepreneur. In reality it's simpler: I can't stop building things. To keep all of it pointed in one direction, there is a north star — and a handful of ventures aligned with it.
Foundry · in the making
xy foundry
A small AI foundry for Berlin: business ideas are stress-tested in three days — with market analysis and clean documentation instead of gut feeling. Out of twenty ideas, four should become seed candidates and one a real spin-out. The search fields: AI, health and education. More about this here soon.
Product studio · a PinkStone brand
fastercode.studio
Business software in days, not quarters: five proven product lines — from CRM to AI operations to a support assistant — adapted to your process and handed over completely, source code included. No vendor lock-in; support only if you want it.
Advisory board
Hangar Strausberg
A startup ecosystem at Strausberg airfield, just outside Berlin: AI, drones, autonomous systems, robotics and dual-use — with real test environments instead of trade-fair booths. I support the project as an advisory board member, because new systems need places where you can actually let them fly.
Personal
Mentoring
A fixed part of my week belongs to people who are building right now: founders and operators. We sort through decisions, product questions, team dynamics — confidential, at eye level, no program, no slides. Sometimes a walk is all it takes.
Workshop
From my workshop.
I build every day — with AI firmly part of the process. Over the past year, that turned into thirty-plus projects I actively co-develop: systems for clients, tools for everyday work, and experiments that are simply fun. Three favorites up front — the rest is in the workshop.
- Projects in the workshop
- 30+
- systems in daily use
- 12
- Pieces with their own page
- 7
Opinion
Three topics that won't let go of me.
AI, health and education — fields where software touches people's everyday lives. I write down what I think about them: a small magazine with three sections, long essays and short ideas. From hands-on building, not from slides.
Recently written
Working together
What we can do together.
I contribute most where building, deciding or investing is involved. An early thought is plenty — concrete doesn't mean finished.
Investment
as an investor who rolls up his sleeves: judgment, network, hands-on work — and sometimes capital.
Board & advisory
when technology, market and organization need to be judged together.
Mentoring
confidential, regular or one-off — for people building under pressure.
Co-building
when deep expertise should become a product or a venture.
Sparring
one concrete decision, a second pair of eyes, an honest verdict.
Early teams
even before product, even before funding — substance counts for more than maturity.
Contact
Write to me.
A short message is plenty — two or three sentences about what's on your mind. Unfinished is explicitly okay.
Thanks for your message. I read every message myself and get back to you directly — no detours.