Wolution Scientific Image Analysis. With my partner Dominik Wuttke I founded a company for scientific image analysis. One of my contributions is a Deep Learning algorithm that can be applied to a large class of problems and is used in practice by researchers in different fields. wolution.com
9dots.de webdesign. During my time as a student, I had a small webdesign company with two friends, which is no longer active. You can find our work on our website 9dots.de, with our long list of references that we did over the years.
Snaptick. An entrepreneurial project during my student times was Snaptick, which was a service to create a personal website from a desktop client in windows. We had a few hundred active users and a few paying customers. The service no longer exists, but a screenshot is here, and of course the internet archive hasn’t forgotten us.