He participated in experiments in the field of elementary particles, among others at CERN. He worked at the University of Warsaw, at the Goethe University in Frankfurt and at Max Planck Institute in Munich. He co-founded several companies commercializing the results of scientific research, the first of which was established in 1987. Currently, Jacek Kosiec is responsible for projects focused on space technologies in Creotech Instruments S.A. He is also the Chairman of the Supervisory Board of the company.