Guillaume brings two decades of deep experience to the cutting-edge of dark matter research. His Ph.D. work was pivotal in the design, commissioning, and initial results of the XENON100 experiment. He has been a driving force behind critical detector systems, notably serving as the architect of the cryogenics for both the XENON1T and XENONnT experiments. Guillaume also played a crucial role as the Analysis Coordinator for XENON1T's first results and spearheaded the development of the liquid-phase purification system for XENONnT. Currently, he is the Technical Coordinator for XENONnT. His expertise further extends to the DarkSide-20k experiment, where he manages the underground argon cryogenics system.