Blacksmith raised a $66 million Series C at a $1 billion valuation to expand the dedicated computing fleet behind its continuous-integration cloud. Sequoia Capital led the round, which Blacksmith announced Oct. 21, with Premji Invest and existing backers Peak XV Partners, GV and Y Combinator participating.
The financing is aimed chiefly at the bottleneck that appears after code is written: builds and automated tests must still finish before engineers can merge changes. Blacksmith says it manages just under 10 megawatts of computing capacity across United States and European data centers and plans to increase that footprint fivefold in 2027.
Customers can move existing GitHub Actions build-and-test jobs to Blacksmith rather than operating the underlying runners themselves. The company writes the scheduling and caching software, buys much of the hardware that executes the jobs and charges by runner minute for self-service usage; enterprise plans add service guarantees and dedicated support.
Blacksmith says its weekly CI workload has risen from 5 million jobs in January to more than 90 million, while annual recurring revenue increased seventeenfold. It reports more than 10,000 customer organizations, including Mercury, Granola, Handshake and LangChain.
The apparent two-month sprint between rounds is misleading: Blacksmith said the $45 million Series B it announced in August had actually closed in March. That financing valued the business at $550 million, while the Series C brings its disclosed total funding to $125 million.
The pressure on testing is not limited to Blacksmith’s customers. Anthropic said in September that its own CI job volume had increased twenty-fivefold in six months and described rebuilding an internal test-selection service after successive fixes failed. Its experience supports the demand premise while illustrating the build-or-buy choice: large developers can create their own systems, GitHub sells hosted runners, and coding agents already execute tests.