Andy Jassy, the Amazon.com leader who is set to take over as chief executive from founder Jeff Bezos later this year, is a longtime acolyte of his boss who helped come up with the tech giant’s most profitable idea: cloud-computing.

Since Amazon Web Services launched in 2006, Jassy has been its chief architect and evangelist, building the business from a nascent idea that was widely questioned in the technology community to a multibillion-dollar business that dominates the internet.