Blacksmith Raises $66 Million Series C at $1 Billion Valuation, Led by Sequoia, as AI-Written Code Drives CI Demand
CI infrastructure startup Blacksmith said on Oct. 21 that Sequoia is leading its Series C at a $1 billion valuation; Fortune reports the round at $66 million, about two months after a $45 million Series B at $550 million. Blacksmith says weekly CI jobs grew from 5 million in January to more than 90 million.
Blacksmith is a bet that AI coding moves the bottleneck from writing software to testing it, a case its CEO makes to Fortune. On Wednesday, October 21, Blacksmith, which runs continuous-integration (CI) infrastructure for building and testing code before it is merged, said Sequoia Capital is leading its Series C at a $1 billion valuation, with Premji Invest and existing investors Peak XV Partners, GV and Y Combinator. Fortune reports the round at $66 million, about two months after a $45 million Series B led by Peak XV at a $550 million valuation.
The growth figures, by source
Blacksmith says weekly CI jobs on its platform grew from 5 million in January to more than 90 million, that its ARR has grown 17x and that more than 10,000 companies use it. Fortune reports the customer count was about 5,000 in August, and that CEO Aditya Jayaprakash said revenue is now "in the tens of millions." The company says it manages just under 10 MW of compute in data centres in the US and Europe and is working to grow that fivefold in 2027.
Blacksmith puts its total raised at $125 million; Fortune puts total funding at about $124.5 million.
Demand, and who could compete
Jayaprakash told Fortune that AI coding tools have made writing code "extremely easy," and that "now the bottleneck has shifted to the second piece, which is: how do I actually validate all this code?" He said CI volume on Blacksmith rose 40% when Anthropic launched Claude Fable 5 in July. Fortune notes that model vendors are expanding their own coding products and that Microsoft-owned GitHub sells hosted machines for CI jobs; Jayaprakash argues Blacksmith is complementary because better models mean more code to check.
Limits
- Growth, ARR and customer figures are the company's own; Blacksmith has not disclosed revenue beyond Fortune's "tens of millions" characterisation from its CEO.
- The $66 million round size is from Fortune; Blacksmith's post does not state it.