CTV company Olyzon has closed a $10 million Series A funding round led by S4S Ventures, the firm co-founded by Sanja Partalo and Sir Martin Sorrell. Existing investors including Eurazeo also participated in the round.
S4S Ventures’ investment is based on the suggestion that the infrastructure layer for CTV media buying has not yet been built, and that Olyzon is positioned to fill that gap.
Olyzon’s platform uses AI agents to continuously qualify CTV inventory, plan media across multiple pipes, and activate decisions directly into existing DSPs, SSPs and publisher ad servers. On the measurement side, the platform normalises signals from multiple sources into composite KPIs, using data from each campaign to refine future optimisation. The company describes this as closing the decisioning loop, connecting planning, activation and measurement into a single platform that operates with a speed and precision that human teams working alone cannot match.
The platform is already live with a number of major agencies and brands, including Publicis, WPP, OMD, Mastercard, Loewe, Audi, McDonald’s and DoorDash. Olyzon positions its technology as complementary to existing infrastructure rather than a replacement, working alongside DSPs and measurement partners rather than competing with them.
The Series A capital will fund product development, an expansion of Olyzon’s US operations, and the opening of a London office, which will be the company’s first foothold in EMEA. The London launch is timed ahead of Cannes Lions in June, where Olyzon has said it will make further announcements on product and partnerships.
Sir Martin Sorrell, co-founder of S4S Ventures and executive chairman of S4 Capital, said the platform sits at the intersection of agentic AI and the consolidation of CTV onto programmatic infrastructure, two forces he described as reshaping the industry. Sanja Partalo, co-founder and managing partner of S4S Ventures, pointed to Olyzon’s combination of deep trading expertise and purpose-built agentic architecture as central to the investment thesis, adding that the company was already delivering results for some of the most demanding agencies and brands in the market.
Olyzon CEO and co-founder Jules Minvielle said the rapid scaling of CTV, marked by a proliferation of pipes, formats and fragmented measurement, had not been matched by advances in decisioning infrastructure. He said AI agents capable of reasoning across that complexity had now reached production maturity, and that Olyzon was built precisely for that moment.
