Blacksmith Raises Sequoia-Led Series C at $1 Billion Valuation to Scale Code Validation

Company's ARR grew 17x since January, with more than 10,000 startups and enterprise companies running builds and tests on its platform.

SAN FRANCISCO, Oct. 21, 2026 /PRNewswire/ -- Blacksmith, the infrastructure platform for building and testing code, today announced a $66M Series C led by Sequoia Capital at a $1 billion valuation, with participation from Premji Invest and existing investors Peak XV Partners, GV and Y Combinator. The round brings Blacksmith's total funding to $125 million and will enable the company to grow its team and expand its compute footprint.

For years, writing code was the slow part of shipping software. With AI coding agents now producing a large and growing share of the world's code, the burden has changed from writing code to validating it. Every change still has to be built and tested before it can be merged, a step known as continuous integration, or CI.

Most companies run CI on general-purpose cloud infrastructure that was never designed for it. As developers push more code, teams hit longer waits for compute, slower builds on older-generation CPUs, and a constant fight between over- and under-provisioning. Anthropic reported last month that its own CI volume grew 25x in six months as Claude took over most of its code output.

"Since Claude Code took off in March, almost every conversation we've had with a large engineering team has started the same way. Developers who used to push three or four pull requests a day are now pushing orders of magnitude more and their CI infrastructure can't keep up. We're grateful to our customers who are trusting us to solve this bottleneck, and excited to partner with Sequoia to solve it at scale," said Aditya "JP" Jayaprakash, co-founder and CEO of Blacksmith.

CI is the most variable workload a company runs: a single customer's demand regularly jumps from zero to tens of thousands of CPUs and back again. Blacksmith has designed every part of its infrastructure stack to absorb those spikes as a matter of routine. Customers switch with a one-line change to their workflow file and never provision, scale or maintain their CI infrastructure again. Developers using Blacksmith see their CI jobs complete twice as fast and at 60% lower cost on average, with zero operational overhead. Since January, the number of CI jobs running on Blacksmith each week has grown from 5 million to more than 90 million, and annual recurring revenue has grown 17x.

"JP and team understood early that as AI agents wrote more code, the infrastructure to build and test it would need to change," said Isaiah Boone, Partner at Sequoia Capital. "What stood out to us was their deep systems expertise and speed of execution. That has translated into a product that helps their customers test and ship their software faster. We believe that foundation gives Blacksmith room to build much more as the demands of software development change."

Blacksmith was founded in 2024 by Jayaprakash, Aayush Shah and Aditya Maru, who met as undergraduates at the University of Waterloo. Shah and Maru were early engineers at Cockroach Labs, and Jayaprakash was an engineer at Faire. All three are developers who have run spiky, large-scale infrastructure before, and they built Blacksmith on the bet that testing code, not writing it, would become the constraint on shipping software.

More than 10,000 companies, including Ashby, Granola, Handshake and LangChain, now run their CI on Blacksmith. The company manages nearly 10 MW of compute across data centers in the United States and Europe and is on track to grow that footprint at least 5x in 2027.

"Blacksmith has significantly reduced the burden of managing our CI runners while cutting our runner costs by roughly 40%, and that doesn't even account for the engineering time we've saved," said Joaquin Borggio, Infrastructure Engineer at LangChain.

To learn more or move your CI to Blacksmith, visit blacksmith.sh. Blacksmith is hiring engineers in New York and San Francisco at blacksmith.sh/careers. Follow Blacksmith on LinkedIn and X.

About Blacksmith

Blacksmith is the infrastructure platform for building and testing code. Companies bring Blacksmith their builds and tests, and Blacksmith runs them twice as fast and at 60% lower cost on average, on infrastructure purpose-built for CI workloads. More than 10,000 companies, including Ashby, Granola, Handshake and LangChain, run their CI on Blacksmith. The company was founded in 2024 by Aditya (JP) Jayaprakash, Aayush Shah and Aditya Maru and is backed by Sequoia Capital, Premji Invest, Peak XV Partners, GV and Y Combinator. For more information, visit blacksmith.sh.

SOURCE Blacksmith