Brewer sits both on the board and in the C-suite of the coffee giant: She was already a Starbucks director when the company tapped her in September 2017 to head up operations and the $15.7 billion Americas business. Now the former CEO of Walmart’s Sam’s Club division is drawing on her retail expertise to reverse a sales slowdown in the U.S. market—a slide that has contributed to a 5% decline in Starbucks stock so far this year. To help, Brewer is focusing on the company’s digital rewards program—membership is up 14% year over year—as well as closing stores in dense urban markets and opening new ones in the middle of the country and the South to expand geographically in the U.S.