Existing generative AI models are built on batch processing: You give the system instructions; it runs computations; then spits back the results.

Now comes a Silicon Valley startup that says it can produce gen-AI video (and other outputs) in real time — a potentially groundbreaking advance: San Francisco-based Reactor, co-founded by Alberto Taiuti and Bryce Schmidtchen, two former technical leads for the Apple Vision Pro AR/VR headset.

The duo have a vote of confidence from Jeffrey Katzenberg, the Hollywood mogul turned investor, who has taken a stake in Reactor through his WndrCo holding company. Reactor has raised a $59 million round of Series A funding led by Lightspeed Venture Partners, with participation from investors including WndrCo, Amplify Partners, Sky9 Capital and FPV Ventures.

Katzenberg says that when he met with Reactor founders and saw their demo, “I was incredibly impressed, if not astounded, by just how innovative their approach is to storytelling tools.”

“Literally every facet of the production pipeline can be enhanced using these tools: live action, TV, film, commercial work, animation – any visual medium can be enhanced by the applications from Reactor,” he says. With the funding, Katzenberg will join Reactor as a board observer.

Katzenberg describes Reactor like this: “It’s a bridge between the model world and real-world applications.”

Reactor says its platform unlocks a new form of media: experiences that are no longer pre-rendered, but generated dynamically and shaped by user interaction. The Reactor platform provides a unified software development kit (SDK) and application programming interface (API) that let developers build real-time interactive applications with “just a few lines of code” — and run them at scale.

“World models are redefining what AI can do, moving from systems that generate content in isolation, to ones that perceive and respond in real time,” says Taiuti, who is Reactor’s CEO. “We are building the critical layer between the model labs and the developers who want to create with them.”

“Our mission is to democratize real-time video generation,” Taiuti says. The company has examples of its system in action on its website at reactor.inc.

Taiuti and Schmidtchen, after they left Apple, founded Reactor in August 2025. “It was germinating in our heads for quite some time,” says Taiuti. “Reactor is the culmination of our entire careers. It feels like we have been building for this moment for some time.”

Text-to-video generative AI systems can take up to 10 minutes to produce 10 seconds of video, says Taiuti. With Reactor, “the time to first frame with our platform is basically nil,” he says. “We have optimized our platform for this content modality — we can generate videos instantaneously. They can be unbounded. They can run as long as you want.”

And Reactor’s platform has applications beyond real-time video, including software development and robotics. “What if software is written this way?” Taiuti muses. In the future, he suggests, “humans are going to interact with pixels, not text.”

Schmidtchen, who serves as Reactor’s CTO, says companies using its real-time AI platform include Overworld, a developer of interactive gaming models. As far as source material, Reactor partners with companies that have trained their own models, and “we take their models and optimize them heavily,” says Schmidtchen. Reactor has worked with over a dozen models from different AI labs.

Taiuti says the company is in talks with major Hollywood studios about deals. “Studios want to train their own models internally,” he says.

Reactor will use the latest tranche of funding to expand internationally as well as in the U.S. to serve large customers. It also expects to invest in expanding its GPU capacity for real-time processing, and spend money on marketing.

Reactor is based San Francisco’s South Park neighborhood and currently has 16 employees. The team includes engineers and researchers from Apple, Netflix, Meta, Google, Adobe, Replicate and Microsoft, who have experience in graphics, real-time systems, interactive media and scaling AI infrastructure.

Bucky Moore, partner at Lightspeed, said in a statement, “Real-time video models are currently inaccessible to developers due to a lack of infrastructure that can reliably serve them. Alberto, Bryce and the team bring a rare combination of real-time systems expertise and product vision to this problem, and we believe Reactor is well positioned to become the foundational platform in this new category.”

Reactor’s partners include Amazon Web Services (AWS), which is providing compute infrastructure and distribution to serve real-time generative video workloads at global scale. Deap Ubhi, global director of technology for startups at AWS, says Reactor is unique in the space right now because they are building an AI inference engine that is agnostic to any model. He says that on a Zoom call, Taiuti used Reactor’s platform to change Ubhi’s face into Albert Einstein’s in real time. “The technology powering that inference engine is pretty powerful,” he says. “That building block is quite compelling and interesting.”

Jason Bennett, AWS’s VP and global head of startups and venture capital, adds, “Reactor’s real-time video platform demands inference infrastructure that can deliver at the speed of interaction, not just the speed of generation, and AWS is unmatched in solving for the latency, scale and reliability that these workloads require.”

Katzenberg, about Reactor’s technology, says, “I’m just quite optimistic this is ultimately going to have a very empowering and successful outcome for Hollywood.” Katzenberg is the former CEO of DreamWorks Animation, which he co-founded after heading Walt Disney Studios and Paramount Pictures. He says he was “schooled” in traditional hand-drawn animation for the better part of a decade and then was “front and center” as CGI arrived and upended that business.

“I am certain we are on the cusp of one of those transformative moments today,” says Katzenberg, adding: “Storytelling always evolves — it’s been that way going back to cave drawings. I look for tools that give storytellers the edge. The human touch is to me still everything.”

Pictured top: Alberto Taiuti (left), Bryce Schmidtchen