Daniel Keller
CPTO · Builder · Pilot
25+ years building technology products. Four exits. Now obsessed with GenAI-native development, longevity optimization, and flying a Cirrus SR22T across Europe.
The Journey
From an Amstrad CPC to four exits
It started with an Amstrad CPC 6128 (branded as Schneider in Germany) — 128 KB of RAM, a 128 KB floppy disk, and game code copied from magazines. I wrote my first neural network in university in 1994, back when "AI" was an academic curiosity, not a product category. Computer Science degree from Regensburg, MBA from the University of Augsburg and Katz Business School in Pittsburgh.
The career that followed was a series of bets on technology-driven transformation: AutoScout24, Ciao!, Zanox/AWIN, Axel Springer, SolarisBank, Visable, Onfido (acquired by Entrust in 2023), and now IDnow. Always in CTO, CPO, or CIO roles — always building. Four of those companies were acquired — with a combined exit value north of $1.6 billion.
Before the tech career took over, I was a competitive rower on the Bavarian team as a teenager. The discipline stuck: show up early, train hard, execute precisely. It turns out that mindset works equally well for building products as it does for pulling an oar at 5 AM.
Present Day
What I'm focused on
GenAI Product Development
Building with Claude Code, Cursor, and local LLMs (Qwen3-Coder on MLX). Pioneering what I call the "Overnight Agent Factory" — parallel agentic workflows that ship features while I sleep. Deep into MCP protocol and three-tier AI architecture patterns.
Longevity Optimization
A structured six-pillar framework: sleep, exercise, eat, mental health, boost, and avoid. Not biohacking theater — data-driven protocols refined over years. Currently building NutriSpan to quantify the longevity impact of everything I eat and do.
Flying
EASA and FAA PPL, Instrument Rating, 10+ years in the air. Based at Schönhagen (EDAZ) near Berlin, flying a Cirrus SR22T across Europe — Alps, Mediterranean, the UK. If I go more than two weeks without being airborne, I get restless.
Side Projects
Things I'm building
I'm a maker at heart. These projects are all built with GenAI-native workflows — Claude Code sessions, parallel agents, and the occasional 3 AM commit from an overnight factory run.
SortFlex
Browser-based 3D configurator for custom holders and mounts. Design it, export it, 3D print it. Built with React Three Fiber, CadQuery, and Cloudflare Workers.
Learn moreNutriSpan
Health optimization app with a Longevity Impact Score. NutriScan food database, personalized protocols. Built with React Native and Expo.
Learn moreFixtureForge
Parametric CAD for manufacturing jigs and fixtures. A B2B SaaS concept exploring browser-based design-to-fabrication workflows.
Concept stageGeneral Aviation
Life at flight level
I caught the flying bug at the start of this century and haven't looked back. What started as a PPL has grown into dual EASA and FAA licenses, an Instrument Rating, and a Cirrus SR22T based at Schönhagen (EDAZ) south of Berlin.
I fly across Europe regularly — threading through Alpine valleys, crossing the Mediterranean, landing at airstrips in the UK. Every flight is captured on GoPro. It's the one activity where my mind goes completely quiet and every decision matters.
EASA PPL(A)
Instrument Rating
FAA PPL
Instrument Rating
Cirrus SR22T
Based at EDAZ
Personal
Beyond the screen
Proud father of three adult kids — Dominik, Annina, and Maximilian — all of whom became software engineers. (I didn't push them. They watched me build things and decided it looked like fun.) Married to my wonderful wife Michi for over 25 years. Based near Berlin, living somewhere between the forest and the runway.
When I'm not coding or flying, I'm tinkering — 3D printing on a Bambu Lab P1S, wiring ESP32 sensors into Home Assistant, programming KNX scenes, or playing guitar badly enough that nobody asks me to stop. I have a persistent curiosity about how things work, which is occasionally inconvenient for household appliances.
Connect
Get in touch
I'm always happy to talk about product leadership, GenAI development, aviation, or longevity. Find me on any of these platforms.