Antithesis

Antithesis provides a deterministic simulation testing platform that runs a complete software system, injects clock, scheduling, network and storage faults, and reports bugs with perfect reproductions and automated root cause analysis. The platform is built on a custom deterministic hypervisor and can be used in CI, the local development loop, or through agent skills, CLIs and APIs.

The website describes customers as engineering teams building mission-critical systems, with examples in capital markets, databases, event streaming, blockchains, ledgers and in-game currency. Customers are referenced by name in testimonials, including Jane Street and Formance. The website offers demo bookings and does not state a pricing or revenue model.

The company was founded in 2018 by Will Wilson and Dave Scherer, who previously worked on deterministic simulation at FoundationDB. It emerged from stealth in February 2024 and announced a Series A led by Jane Street in December 2025. Its careers page lists offices in Washington DC, London and San Francisco; open roles on the careers page are concentrated in Vienna, Virginia, London and San Francisco, covering software engineering, solutions engineering, sales, marketing and operations.

Product: Deterministic simulation testing platform with fault injection, perfect bug reproduction, automated root cause analysis and CI, agent skill, CLI and API integrations.