Mark J. Day served in many roles over his18-year tenure at iRhythm Technologies (IRTC), most recently as Chief Technology Officer from 2022-2024, and previously as Executive Vice President of Research & Development from 2012-2022, a role that also held executive responsibility for Manufacturing, Regularly and Quality and Intellectual Property

throughout iRhythm’s transition from startup to public company. Previous to joining iRhythm as a seven-employee startup in 2007, Mark worked in the Cardiac Rhythm Disease Management division of Medtronic, Inc. and, prior to that, was the Chief Technical Officer of CarePages, Inc., a blogging site for patients. In addition, Mark served as an independent board member for Circle Cardiovascular Imaging from 2016 through 2022. Mr. Day has a M.B.A. in Marketing from the Wharton School, University of Pennsylvania, a Ph.D. in Computation Flow Physics from Stanford University, and also received a M.S. from Stanford, and a B.Sc. from Queen’s University, both in Mechanical Engineering.