Will Wilson wants to make sure the software running everything from your bank account to your favorite crypto exchange actually works—and his company Antithesis is rethinking how software has been tested for the last 80 years.

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Wilson, the co‑founder and CEO of Antithesis, first made his name at FoundationDB, a company that created special testing systems that let teams safely rehearse years of real‑world problems in a fake environment, to catch bugs before customers ever saw them (FoundationDB was acquired by Apple in 2015). That idea—stress‑testing code inside a simulated universe where everything that can go wrong does—is now the core of Antithesis, a deterministic simulation testing platform that runs fully automated, parallel tests that can compress years of production behavior into hours.

“Software increasingly controls literally everything,” Wilson told Fortune, pointing to financial markets, banking websites, smartphones, and even nuclear power plants. The traditional model of writing code and then trying to think of every possible edge case “is totally broken,” he argued, because failures come from situations engineers did not anticipate. Antithesis runs customer systems in a controlled simulation where hardware failures, network glitches, and bizarre timing issues are constantly injected to see how the software behaves.

That pitch has resonated with some of the most demanding buyers in finance and crypto. Antithesis is already used by organizations whose systems “cannot fail,” including quantitative trading giant Jane Street (also one of its lead investors), the Ethereum network and MongoDB.

In December 2025, the Northern Virginia–based startup announced a $105 million Series A, led by Jane Street—which is both an investor and a user—alongside Amplify Venture Partners, Spark Capital, Tamarack Global, First In Ventures, Teamworthy Ventures, Hyperion Capital and angels including Stripe cofounder Patrick Collison, Dwarkesh Patel and Sholto Douglas.

The capital follows more than five years of R&D funded by a $47 million seed round raised while Antithesis operated largely in stealth, and $30 million in funding in February 2025 led by Amplify Partners. Antithesis, founded in 2018 and publicly unveiled in 2024, also made its debut this year on the Forbes Fintech 50, which reports that the company has landed about 40 clients, including trading firms where software glitches can translate into large financial losses.

Winning over these clients and investors, Wilson added, has required a studied lack of hype. “Don’t be too thirsty and don’t over promise,” he said. When he talks to prospects, he says he is candid about his product’s weaknesses: “Every product sucks at something. I’m just going to tell you what it is.”

While AI code‑generation models race ahead, Wilson sees a less crowded—and ultimately more durable—opportunity in everything that happens after the code is written.

“AI is eating part of the software development life cycle…which was actually never the slow part or the hard part,” he said. “There’s a world in which…we end up being a really, really significant part of how everybody on earth develops and ships software.”

See you tomorrow,

Lily Mae Lazarus

X: @LilyMaeLazarus

Email: lily.lazarus@fortune.com

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Startup Antithesis turns years of real-world chaos into hours of simulated mayhem—and key trading firms and crypto networks are paying close attention