Multimillionaire tech guru Bryan Johnson says that if he hadn’t sold his payments company Braintree to PayPal in 2013 and became obsessed with anti-aging, he may well have ended up devoting his ...

Bryan Johnson earned his fortune as the founder of the online and mobile e-commerce payment provider Braintree. In 2012, Braintree acquired Venmo for $26 million. In 2013, PayPal (then a unit of ...