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SAN FRANCISCO, March 10, 2026 - TestBox, the GTM Infrastructure platform for B2B software companies, today announced a $12 million Series A funding round led by Airtree, with participation from SignalFire, Skip Capital, Glitch Capital, and K8. The raise brings TestBox's total funding to $27 million.
The company also announced three new products: Data Generator, Surface Editor, and Sandbox Copilot; plus the formal definition of GTM Infrastructure as an emerging software category.
TestBox is used by GTM teams at Intuit, Gong, and Apollo to run live demos and product sandboxes. Customers have seen win rates improve by 2-3x.
"AI is raising the bar for proof, not lowering it," said Sam Senior, CEO and Co-founder of TestBox. "Buyers, and soon their agents, will demand real product, on demand, at every stage of the journey. Everyone can fake a great product but nowadays you need to prove you do what you say. We raised this round to build the infrastructure that makes proof possible at scale."
The Problem
GTM teams are still running on broken infrastructure. Staged environments that break mid-call. Synthetic data that looks fake the moment a buyer clicks the wrong thing. Sandbox setups that take weeks of engineering time to build. As AI makes it easier than ever to generate slick-looking software, buyers have become more skeptical. The old playbook of polished, scripted demos no longer builds trust. It erodes it.
The Platform
Powered by the Product Graph — an AI-native map of a product's schema, APIs, flows, and dependencies — TestBox lets GTM teams generate live, working product environments in minutes. No engineering bottlenecks. No smoke and mirrors. As AI agents begin running autonomous software evaluations on behalf of buyers, companies with real, provable environments will win those evaluations. No one else won't make the shortlist.
New Products
- Data Generator generates realistic synthetic datasets instantly, so every demo and sandbox reflects the buyer's actual world from the first click. Available free today at testbox.com/data-generator.
- Surface Editor gives GTM teams full control over how their product looks in any demo or sandbox so they can personalize to each buyer's use case.
- Sandbox Copilot is a 24/7 AI Sales Engineer that gives every buyer a technical expert on demand. Buyers can explore the real product themselves, at any stage, without waiting for a sales call.
Availability
Data Generator is available free today at testbox.com/data-generator. Surface Editor and Sandbox Copilot are available to all TestBox customers. To learn more, visit testbox.com.
About TestBox
TestBox provides GTM Infrastructure for B2B software companies. Powered by the Product Graph, GTM teams generate live demo environments, realistic synthetic data, and interactive sandboxes without engineering bottlenecks. Customers including Intuit, Gong, and Apollo use TestBox to run their full GTM motion.
Fake nothing. Prove everything.
Learn more at testbox.com.
Press contact: hello@testbox.com
