Blacksmith Raises $66M at a $1B Valuation to Speed Up Code Testing
Blacksmith (blacksmith.sh) raised a $66 million Series C led by Sequoia Capital at a $1 billion valuation. Fortune first reported the round, and the company announced it on its blog. Existing investors Peak XV Partners, GV, and Y Combinator also put in money. GV had previously invested in the company's seed and Series A rounds.
The Series C closed about two months after Blacksmith's $45 million Series B, which Peak XV led at a $550 million valuation, according to Fortune.
Blacksmith runs continuous integration (CI) for its customers. CI is the step where every code change gets built and tested before it is merged. Companies running GitHub Actions can move their jobs to Blacksmith's machines by changing one line in their workflow file. After that, they don't have to provision or scale the servers themselves. On average, jobs finish twice as fast and cost 60% less, the company says. Customers include Mercury, Granola, Handshake, and LangChain.
The pitch is tied to the growth of AI coding tools. Agents can produce pull requests much faster than people can, but every change still has to pass through CI. In his announcement post, CEO Aditya (JP) Jayaprakash pointed to Anthropic, which reported that its CI job volume grew 25x in six months as Claude took over most of its code output. Jayaprakash said Blacksmith is starting to see the same pattern across its own customers.
"JP and team understood early that as AI agents wrote more code, the infrastructure to build and test it would need to change."
Isaiah Boone, Partner at Sequoia CapitalSince January, the number of CI jobs Blacksmith runs each week has grown from 5 million to more than 90 million, and annual recurring revenue is up 17x. More than 10,000 companies now use the service. CI demand comes in sharp bursts: a single customer can go from zero to tens of thousands of CPUs and back down again. Blacksmith says it has spent most of the past three years building systems that can handle those spikes.
All three founders studied computer science at the University of Waterloo. Jayaprakash previously worked on search infrastructure and ads at Faire. Co-CTO Aditya Maru and CTO Aayush Shah both came from Cockroach Labs, where Maru built disaster recovery features for the database and Shah worked on replication. The company went through YC's Winter 2024 batch.
Today Blacksmith manages just under 10 megawatts of compute across data centers in the U.S. and Europe. It plans to grow that footprint fivefold in 2027.