(Bloomberg)—Apple Inc. named Jeff Williams chief operating officer as part of several key appointments designed to strengthen the management team and elevate the importance of chip design.

Johny Srouji was promoted to senior vice president for Hardware Technologies, and Phil Schiller, senior vice president of worldwide marketing, will also take on leadership of the App Store, the company said in a statement.

“Jeff is hands-down the best operations executive I’ve ever worked with, and Johny’s team delivers world-class silicon designs which enable new innovations in our products year after year,” CEO Tim Cook said in the statement.

Williams, who has been in charge of Apple’s supply chain, service and support since 2010, is filling the post Cook himself held under Steve Jobs. A 17-year veteran, Williams joined the company in 1998 as head of worldwide procurement, and was named vice president of operations in 2004. He also helped shepherd the launch of the iPhone and supervises the Apple Watch.

The promotion of Srouji is a testament to the widening importance of chipmaking to Apple. Srouji joined Apple in 2008 and led the development of the A4 chip, which went on to power iPads and a generation of iPhones. Heralded by the Haaretz newspaper as the highest ranking Israeli in Silicon Valley, Srouji previously held senior positions at Intel Corp. and International Business Machines Corp., No. 13 in the Internet Retailer 2016 B2B E-Commerce 300. He’s a graduate of Technion, Israel’s Institute of Technology.

Tor Myhren is also joining Apple in early 2016 as vice president of marketing communications, with responsibility for Apple’s advertising efforts. Myhren was previously chief creative officer at Grey Group New York, an advertising agency. Apple is No. 2 in the Internet Retailer 2015 Top 500 Guide and No. 3 in the B2B E-Commerce 300.