Sridhar Ramaswamy, senior vice president of advertising and commerce at Google, is leaving the firm to join Silicon Valley venture capital firm Greylock Partners. Ramaswamy, who has spent the last 15 years at Google, oversaw the companys core advertising and search businesses.

The move was announced by Greylock Partners and was confirmed by Google following market close yesterday. Ramaswamy will become a venture partner at Greylock, initially focusing on companies working in big data, AI & machine learning, and analytics.

“Our mission is to be the best partners for entrepreneurs who want to start and build market-defining, enduring technology companies,” said a Greylock Partners spokesperson. “Sridhar exemplified the kind of person we look for as we work towards that mission. Its a privilege for us to have the opportunity to work closely together, as he starts the next chapter of his professional career.”

At Google, Ramaswamy helped Google Ads scale from $1.5bn (£1.16bn) in revenue in 2003 to more than $100bn in current annual revenues. He spearheaded the development of new and innovative businesses in shopping ads, travel, mobile, video ads and app install ads, and was instrumental in the pivot from desktop to mobile search. Prior to joining Google, he was director of engineering at E.piphany, and held various positions at Bell Labs, Bell Communications Research and Lucent Technologies.

“I have been extremely privileged to have spent the past 15 years at Google, where I focused on starting and scaling new businesses and platforms,” said Ramaswamy. “I have always been drawn to earlier stage entrepreneurial projects and becoming a venture partner at Greylock in an exceptional way to explore these types of opportunities. I am excited by the prospect of working with the amazing partners at Greylock and the great entrepreneurs that they have backed.”