Julien received his M.D degree in 2012 from the University Of Geneva in Switzerland where he worked on human olfaction following nasal surgery and the control of genome expression in yeast cells. In 2013, he carried out an Ear, Nose and Throat (ENT) residency at Luxembourg Hospital Center in Luxembourg. He won the “Junior Scientific Excellence Prize” for the development of a Smell and Taste clinic in Luxembourg to treat chemosensory disorders and promote research in this field. In 2014, he joined the Rockefeller University Hospital in New York (USA) as an instructor in clinical investigation (clinical scholar) at the Vosshall's Laboratory of Neurogenetics and behavior. There, he worked with Andreas Keller and Leslie Vosshall and invented SMELL-RS, a universal smell test that may help diagnose patients with olfactory dysfunction. In 2017, he returned to Geneva to continue his ENT residency at the Geneva University Hospitals (Switzerland) and trained with Basile Landis, an expert in clinical olfaction. In 2019, he was promoted young physician-scientist by the University of Geneva - Faculty of medicine with 50% protected time to conduct research at the bench and patient's bedside. In Pascal Senn's Inner Ear and Olfaction Laboratory, he carried out research on olfactory neuroregeneration to find a cure for patients with post-traumatic smell loss. He received several international awards such as the "European Chemoreception Research Organization Young Investigator Award" in 2018 and the "Clinical olfactory working group - German ENT society Award" in 2019.