im McKelvey was a glassblower when he created the idea for the payment platform Square (now Block, Inc.). He was furious that he couldn’t accept certain credit cards as an artist and contacted a former colleague and Twitter co-founder Jack Dorsey to solve the problem. What took three weeks to build became a three-year journey of creating Square into a banking disruptor inspired by McKelvey’s frustrations. In the 15 years since McKelvey teamed up with Dorsey, Square has grown into a billion-dollar business and beat the world’s best company at absorbing startups—Amazon.