Stephan Uhrenbacher is a mechanical engineer by training, and a pilot and aircraft owner by choice.
He is building Density Ventures into a permanent home for small, certified European manufacturers of mission-critical components — companies whose products cannot fail, and whose certifications took decades to earn. The plan is to acquire and hold, not to flip: keep the name on the building, keep the people, keep the certification. He is starting with aviation and looking for the first company now.
Over twenty years, Stephan founded and led four international companies. Qype, a local-reviews site that led the European market, was sold to Yelp. Flio became the most used airport app in the world. 9flats.com competed globally with Airbnb. Avocado Store, which he cofounded, built an ecommerce marketplace for sustainable living. Earlier in his career he held senior operating roles at DocMorris.com, Europe’s largest mail-order pharmacy; at Bild.de as Head of Content; at lastminute.com as Head of Northern Europe; and at Bertelsmann, where he founded one of Germany’s first online travel businesses.
Since May 2025 he has served on the board of Tucows Inc., listed on Nasdaq — governance of a public compounder, not a startup board seat.
In aviation, Stephan leads Future Aero Lab and works alongside mentors and engineers from Boeing, Airbus, Lufthansa, Embraer and Pratt & Whitney. It is the network the first acquisition is likely to come from.
Two things run alongside the main work without being it. He advises a small number of AI startups in Europe and Canada and is a Fellow at the AI Centre ARIC in Hamburg. And for close to a decade he has coached a handful of founders through the hardest stretches of running a company — work he still does, quietly, for people who already know him.