Youssef Daali graduated as a pharmacist from the UNIGE in 1995, then obtained an FPH Specialist Certificate in Pharmacy. In 2001, he obtained a PhD in pharmaceutical sciences, also from the UNIGE. He joined the HUG in 2002 as project leader and Head of the clinical pharmacology and toxicology laboratory, working on identifying the genetic and environmental sources of variability in response to drugs. In this context, he developed prediction and simulation tools in vulnerable populations using physiology-based pharmacokinetics (PBPK). 

He was appointed Privat-Docent in 2014 at the Faculty of Science, and in 2016 at the Faculty of Medicine. He was also awarded the title of SKPT clinical pharmacologist by the Swiss Society of Clinical Pharmacology in 2014. He is a member of the Interfaculty Centre for Translational Biomarker Investigation (CITB) and the Geneva Platelet Group at the Faculty of Medicine, and a scientific member of the Cansearch Foundation. He is also director of the DAS in clinical trial management and the MAS in clinical discovery and development at the UNIGE. In 2019, he was appointed assistant professor in the Department of Anaesthesiology, Pharmacology, Intensive Care and Emergency Medicine at the UNIGE Faculty of Medicine, before being appointed associate professor in July 2025.