Caywood, 30, joined Barclays this month after almost three years at the digital bank, where she held the key post of overseeing the financial services used by the site 400,000 customers.
She becomes a managing director of the high street lender in charge of consumer strategy.
US-born Caywood oversaw the bank’s Marketplace operations, where it sells such products as investment, insurance and mortgage services to its customers, usually through third parties.
Starling Bank added: “Ben will be responsible for Marketplace product development, while Helen will take on responsibility for commercial relationships.”
Prior to Starling, Caywood spent just under four years working in California as a global product manager for cloud accounting firm Xero, and before that as a product manager for financial software business Intuit.
Caywood studied cognitive science at Stanford University, and earlier, at Pepperdine University, where she also founded its Entrepreneur Club.