Brian Lesser is joining the board of InfoSum, a U.K.-based software as a service (SaaS) company.

InfoSum has been working to stake a claim in identity and data at a time when the industry is moving away from third-party cookies and will need to apply more first-party data to identify consumers.

Lesser stepped down as CEO of AT&T’s ad unit Xandr in March. Prior to Lesser’s departure, Xandr took a stake in InfoSum.

“I have always been incredibly impressed with InfoSum’s privacy-first stance within the industry. Now, more than ever, marketers and brands are looking for safe, secure, and trusted solutions for their identity and data applications,” Lesser said in a statement.

InfoSum CEO Nicholas Halstead said he does not believe one company should own identity.

Lesser joined AT&T in 2017 amid its acquisition of the formerly known Time Warner to help the telecom giant reinvent TV advertising. Prior to Xandr, Lesser led all of Group M’s North American business.