AI is writing more code than ever — and somebody has to test it. Blacksmith, a startup providing continuous integration infrastructure for automated software testing, has raised $66 million in a Series C round led by Sequoia Capital at a $1 billion valuation.
The round comes roughly two months after Blacksmith raised $45 million in a Series B led by Peak XV Partners at a $550 million valuation, bringing total funding to about $124.5 million. Founded in 2024 by Aditya Jayaprakash, the company runs its own servers across data centers worldwide rather than renting cloud infrastructure, and builds software that cuts repetitive setup work during testing.
The boom is a direct side effect of AI coding assistants like Cursor, GitHub Copilot and CodeRabbit: as developers generate far more code, the bottleneck shifts from writing software to validating that it works.
The numbers behind the valuation are striking. More than 10,000 companies now use the platform, up from about 5,000 in August, with customers including Granola, Handshake, Supabase and LangChain. Weekly code validation checks surged from five million at the start of 2026 to roughly 90 million, while annual recurring revenue grew seventeenfold over the same period. Jayaprakash says testing volumes jumped another 40% after the July launch of Anthropic’s Claude Fable 5 model.
Most of the new capital will go toward expanding computing capacity. The company employs around 40 people across San Francisco and New York and plans to reach about 75 by the end of 2026. It competes with established testing platforms such as LambdaTest as well as GitHub’s hosted CI — a sign the battle for the AI developer stack is just beginning.
Source: MarTech AI
