In the first major management change in five years, Google will replace its advertising chief Sridhar Ramaswamy who spent 15 years at the company, reported Bloomberg on Monday. Prabhakar Raghavan, head of Google’s business-applications unit, will take over from Ramaswamy on Friday, the company said in a statement.

Ramaswamy, senior vice president of advertising and commerce, has been the driving force in helping Google Ads increase its annual revenue from $1.5 billion in 2003 to more than $100 billion annual revenue until the second quarter of 2018. He was also instrumental in developing shopping, travel, mobile, video advertisements, and app install advertisements.

Meanwhile, Raghavan, vastly experienced in the fields of search technology and artificial intelligence research, will oversee product and engineering for Google. The 58-year-old will also be responsible for maintaining the growth at the company’s search and display ad operations and developing new revenue sources. Raghavan, who joined Google in 2011, was drafted in three years later to oversee Google’s suite of cloud-based business apps, including Drive, Docs and Hangouts.

Raghavan said his aim will be to maintain continuity in the ad business, which generates most of the revenue for Google and its parent company, Alphabet Inc. “The ecosystem remains strong. The business remains strong,” he said. “My focus is on how to take that fantastic machine and keep it going rather than being a bull in a china shop.”

Google Chief Executive Officer Sundar Pichai said in a statement that he “can think of no better person to lead our monetisation efforts” than Raghavan, reported CNBC. “Prabhakar has incredible management experience, and the deep technical expertise to match,” he said.

Ramaswamy will join Greylock Partners as a venture partner, the company said in a statement. “Sridhar will initially focus on working with and investing in companies that leverage data at scale, Artificial Intelligence/machine learning, and analytics to deliver the next generation of insights and capabilities for consumers or enterprises,” it said.

“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,” Ramaswamy said. “I have always been drawn to earlier stage entrepreneurial projects and becoming a venture partner at Greylock is an exceptional way to explore these types of opportunities.”