Flees started her career in the automotive industry 35 years ago within General Motor's GMC Truck division. After 17 years at Bain & Company, a global strategy consulting firm, Flees spent nearly a decade at Walmart where most recently she led all aspects of Walmart's Health & Wellness business across more than 4,800 locations. She joined Walmart to lead corporate strategy and development, and later moved into leadership roles that included the incubation of new retail capabilities via the deployment of emerging technologies, strategic partnership development with companies such as Google and Microsoft, and the leadership of the pharmacy and optical business of Sam's Club.