Jason Hassenstab, PhD is a Professor in the Departments of Neurology and Psychological & Brain Sciences at Washington University in St. Louis, USA. He is the director of the Cognitive Technology Research Laboratory (CTRLab) and also directs the Cognition Cores for the Dominantly Inherited Alzheimer Network (DIAN), the DIAN Trials Unit (DIAN-TU), and the Knight Alzheimer’s Disease Research Center. Prof. Hassenstab is also the Principal Investigator of the ARC-DS study, an international multisite study of Down syndrome-associated Alzheimer disease with performance sites in EU, UK, South America, and the United States. His research areas have focused on cognitive and biomarker studies of aging and Alzheimer’s disease, with a specialization in digital approaches for measuring cognition and behavior. The CTRLab developed the Ambulatory Research in Cognition (ARC) smartphone platform, which applies principles from ecological momentary assessment and experience sampling to capture cognition, sleep, and physical activity. The ARC platform is currently deployed in DIAN, DIAN-TU, the Knight ADRC, and in several collaborations including industry-led clinical trials for AD therapeutics. Prof. Hassenstab maintains active collaborations across several related disciplines, including neuropsychiatry, frontotemporal lobar degeneration (FTLD), sleep research, and developing novel digital approaches for studying normal aging. He has over 150 peer-reviewed publications and has been continuously funded by the National Institutes of Health and private foundations since 2008. One of his greatest joys is mentoring trainees at all levels and fostering international collaborations.