When Jules Minvielle describes the state of connected TV advertising, he reaches for a phrase that's become something of an industry mantra: "massive fragmentation." But unlike the usual chorus of complaints about streaming's splintered landscape, Minvielle thinks he's built the connective tissue the market has been missing.
His Paris-based startup, Olyzon, just closed a $10 million Series A led by S4S Ventures—the investment vehicle co-founded by advertising titan Sir Martin Sorrell and Sanja Partalo. The round, announced May 27, 2026, also drew participation from existing backer Eurazeo, along with newer entrants Cassius Capital and Ventech, according to Adweek.
The funding lands Olyzon in the thick of a curious moment for streaming advertising. Money is pouring in—eMarketer projects U.S. CTV ad spending will hit $37.95 billion this year, up 14.5%—yet buyers are still stitching together campaigns across a patchwork of platforms, publisher inventories, and walled gardens that resist easy coordination. Olyzon's proposition: AI agents that sit atop the existing infrastructure, orchestrating decisions across demand-side platforms, supply-side platforms, and publisher ad servers without replacing any of them.
What S4S Sees in the Plumbing
S4S Ventures has made a bet on infrastructure—specifically, the kind that doesn't show up in flashy Super Bowl spots but makes the whole apparatus run more smoothly. Despite the billions flowing into CTV, there's no unified decisioning engine, no single layer that normalizes signals and closes the optimization loop in real time. Olyzon positions itself as exactly that: an "agentic decisioning layer" that qualifies inventory, plans campaigns at the program level, and executes continuously.
It's a managed service model for now, and the client roster suggests traction with the establishment. WPP, Publicis, OMD. Mastercard, Loewe, Audi, McDonald's, DoorDash. Olyzon says it's reaching north of 5 billion monthly impressions, though the company declined to share its Series A valuation—a detail that would help gauge just how seriously investors are pricing the opportunity.
Moving Fast, Perhaps Too Fast
Minvielle, who founded mobile ad firm Mozoo back in 2010 and later served as COO at Ogury, launched Olyzon in 2024 alongside Martin Danet and Mathieu Desvé, the company's CTO. The trajectory since has been brisk. Seed round in July 2024. A $5 million extension led by Cassius Capital in June 2025. U.S. expansion in April 2025. Integrations with measurement player Innovid and with Swivel for agent-to-agent activation using something called the Ad Context Protocol.
Now comes a London office, timed to open ahead of Cannes Lions in June—a savvy bit of positioning for a company courting the global agency crowd. The headcount stood at over 30 as of March; whether that figure has grown in the months since is anyone's guess.
The timing does align with broader industry winds. For the first time, eMarketer forecasts that U.S. CTV upfront ad commitments will surpass primetime linear this year: $17.73 billion versus $16.98 billion. IAB pegs overall CTV advertising growth at 13.8%, while Dentsu's outlook names CTV and video among the fastest-growing channels globally. Olyzon itself commissioned eMarketer research in January showing nearly 80% of surveyed marketers ready to bump CTV budgets by at least 11%—assuming transparency and unified buying tools improve. A convenient finding for a company selling exactly that.
The Orchestration Play
What Olyzon is attempting isn't entirely new. The ad ecosystem has long been littered with middleware layers promising to harmonize chaos. The difference, perhaps, is one of timing and emphasis. The company isn't building another DSP or measurement suite; it's betting that buyers want something that sits above the stack, making the existing tools talk to each other more intelligently.
Whether AI agents are the answer—or just the latest rebranding of programmatic optimization—remains to be seen. The CTV market is notoriously fragmented, and fragmentation tends to favor those who can consolidate or simplify. Olyzon is betting it can do the latter without needing to own the former.
The company says it will unveil additional product updates at Cannes Lions. Until then, the Series A gives it runway to prove the thesis, expand in the U.S., and see whether the orchestration layer it's pitching resonates beyond the early adopters who've already signed on.
For now, at least, Sorrell and his co-investors are wagering that the plumbing—unglamorous as it is—might be where the real value accrues.
