Patrick Fassnacht started in Experimental Nuclear and Particle Physics at the University of Strasbourg (France) in 1979. From Nuclear Physics he moved to Intermediate Energy Physics participating to various experiments in the domain of “coherent” pion production and searches of multibaryonic states at the CERN SC and at SATURNE (Saclay/France). In 1984 he got his PhD diploma of “Docteur Es-Sciences”. When joining the CPPM at Marseille he moved to High Energy Physics joining the CPLear collaboration (focus on CP violation in the 3??channel) and finally the ATLAS experiment. To the latter he contributed as Test Beam coordinator and later for six years as Technical Coordinator of the ATLAS Liquid Argon Calorimeter system. He was responsible for getting the calorimeters assembled, integrated into the cryostats and commissioned. From April 2004 onwards, for a period of more than six years, he was acting as CERN ATLAS Team leader. During that period he had interactions with the numerous ATLAS Users coming to CERN; at that time he started to establish strong collaboration with some countries from the Middle East and North Africa. Since late 2010 he is also the CERN Scientific Coordinator of the AIDA program.