Ari Belliu

Ari Belliu is a marketing and advocacy leader at Prebid.org, the open-source header bidding wrapper that serves as critical infrastructure for programmatic advertising across thousands of publishers worldwide. As VP of Marketing, Belliu drives awareness and adoption of Prebid's community-driven technology, positioning it as a transparent alternative to proprietary ad tech solutions in an ecosystem increasingly shaped by walled gardens. Belliu is a vocal advocate for open-source principles in AdTech, working to educate publishers, agencies, and industry stakeholders on the strategic and economic advantages of transparent, community-governed technology. Their work at Prebid sits at the intersection of marketing, policy advocacy, and ecosystem development, helping to sustain and grow one of the most widely deployed open-source projects in digital advertising. Through speaking engagements, industry outreach, and content initiatives, Belliu contributes to the broader conversation around publisher monetization, programmatic transparency, and the role of open standards in counterbalancing the consolidation of ad tech power among a handful of dominant platforms.

• Leads marketing strategy for Prebid.org, one of the most widely deployed open-source projects in the global AdTech ecosystem
• Advocates for open-source and transparent programmatic solutions as an alternative to proprietary walled garden technologies