Jan-Stefan was born in South Africa in 1972 and obtained his medical degree (MB, ChB) in 1996 at the University of the Free State. As medical officer/registrar in Urology he became involved in clinical research and joined South Africa Clinical Trials/QdotPharma (later Parexel) as clinical investigator and clinical projects manager covering phase I to phase IV clinical trials in various therapeutic areas in 2000. In 2006 he returned to academia as medical research officer in the Division of Clinical Pharmacology, University of Cape Town, focussing on PK and PKPD in HIV, malaria and tuberculosis. He was a researcher in the Pharmacometrics group, Uppsala University from 2009 to 2011. In 2012 he joined Astellas Pharma EU in Leiden, The Netherlands, as pharmacometrician and medical monitor (urology, uro-oncology and pain therapies). From 2016 to 2022 he worked at Eli Lilly and Company as pharmacometrician and project leader spanning preclinical/translational to post-registration phases for various therapeutic areas (including oncology, diabetes, and gene therapies). Jan Stefan lives in London, United Kingdom.