CI cloud Blacksmith raises Series C at a $1 billion valuation led by Sequoia

Blacksmith, a CI cloud for software teams that is about three years old by its own account, is raising a Series C led by Sequoia Capital at a $1 billion valuation, co-founder and chief executive Aditya Jayaprakash said in a post on the company's blog on October 21.

How it started

The company said in an August post that it began about two and a half years before then, with the goal of building a CI cloud, meaning purpose-built infrastructure to run continuous integration workloads, the build-and-test step every code change goes through before it is merged. Jayaprakash is listed in the posts as co-founder and CEO. The posts reviewed do not name the other founders or describe their earlier jobs.

Its product runs a customer's CI jobs on Blacksmith's own compute. "Companies bring us their CI workloads, and we run them faster than they could anywhere else, with zero operational overhead," Jayaprakash wrote on October 21.

How it grew

Blacksmith said in its Series B post, published August 12, that it had raised a $45 million Series B led by Peak XV, with existing investors Y Combinator and GV, at a $550 million valuation. It said the round was raised in March 2026 but not announced until August. At that time, more than 6,000 companies ran CI on Blacksmith.

The Series C post says the round includes Premji Invest and existing investors Peak XV Partners, GV and Y Combinator, bringing total raised to $125 million. The company said more than 10,000 companies now use it, including Mercury, Granola, Handshake and LangChain.

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 17 times, the company said. Blacksmith manages just under 10 megawatts of compute across data centers in the US and Europe.

The company ties the growth to AI coding tools. "Anthropic wrote last month that its CI job volume grew 25x in six months as Claude took over most of its code output," Jayaprakash wrote, adding that Blacksmith sees the same trend across its customers. The Anthropic figure is the company's account of another firm's statement and was not checked against that firm's own publication.

In the August post, Jayaprakash also described a customer complaint the company hears: "Our developers adopted Claude Code, PR volume increased 4x, and our CI infrastructure can't keep up." Blacksmith said it had launched a cloud coding agent called [code]smith.

What the founders say

"Writing code used to be the slow part of shipping software. It isn't anymore," Jayaprakash wrote in the Series C post. He described CI as the spikiest workload a company runs: "A single customer's demand regularly jumps from zero to tens of thousands of CPUs and back again, and we have spent most of the last three years building infrastructure that absorbs that as a matter of routine."

What's next

The company said the money will go toward scaling its team and growing its compute footprint, and that it is working to grow that footprint five-fold in 2027. In the August post it said it was hiring in New York and San Francisco.