Adelphic Mobile, the Waltham-based mobile ad targeting startup, is getting a new CEO. Michael Collins, until now CEO of the mobile marketing agency Joule, will be taking the top job at Adelphic starting May 20. Co-founder Changfeng Wang will be moving from CEO to CTO, according to sources.

“Adelphic has an amazing technical and product team with a clear vision for what to build,” said Rich Miner, Google Ventures General Partner and Adelphic board member, in a release. “As one of the most respected leaders in mobile advertising, Michael complements the team. His skills and expertise will be invaluable as Adelphic implements the platform for top publishers and advertisers.”

The company says the shift reflects its readiness to begin scaling the business quickly and globally, having spent the bulk of its efforts since its founding in 2010 on product and customer development.

Collins, who lives in Connecticut, will be working from Boston at least four days a week.

Adelphic uses predictive modeling to better target mobile advertisements, using information about content along with some demographic information to draw statistical inferences about the user. It has raised $12 million thus far, from Google Ventures and Matrix, including a $10 million Series A back in December 2012.