JPMorgan Chase’s growth depends on responding to digital-banking demand in much the same way the staff at Starwood’s W Hotels aspire to handle requests from overnight guests: By providing whatever, whenever.

The New York-based lender, the largest in the U.S., will increase its technology spending 15 percent this year to $10.8 billion, with most of it going toward enhancement of mobile and web-based services in its four main lines of business: consumer, commercial, and investment banking, and wealth management.