Max Keßler studied mechatronics at the University of Stuttgart and built the first electric rollator while studying. He has a broad technical knowledge from web development through electronics to mechanics. Max Keßler worked for several years at the Fraunhofer Gesellschaft in product development as well as a student consultant. He is responsible for the electronics and the software of the ellos. He is currently completing a postgraduate course in the field of patent engineering, in order to be able to carry out as many of the necessary activities as possible for a patent application in the case of further inventions.