Apple CEO Tim Cook is about to take over one of the most significant parts of Apple’s business: its design team. The team currently reports to COO Jeff Williams, but once Williams begins his just-announced retirement “late in the year,” the design team “will then transition to reporting directly to Cook,” Apple says.

Apple’s chief operating officer plans to hand the role off this month and retire later this year after roughly a decade as the tech giant’s No. 2 under Chief Executive Tim Cook.

Apple CEO Tim Cook, who has led the company since 2011, is expected to stay on for at least three more years, but succession questions are gaining traction.