Blacksmith hits unicorn status with $66M Series C for AI-era CI cloud

Blacksmith, a San Francisco startup that runs a dedicated cloud for continuous integration, has raised $66 million in a Series C round led by Sequoia Capital, pushing its valuation to $1 billion. The funding, announced today, follows a $45 million Series B in August and brings the company’s total raised to $125 million.

The round included participation from Peak XV Partners, Y Combinator, and GV. SiliconANGLE reported that Blacksmith now serves over 10,000 companies, up from 5,000 in August, and processes about 90 million code checks per week—an eighteenfold increase since early 2026. Annual recurring revenue has grown seventeen times over the same period, with some enterprise customers spending seven figures annually.

Blacksmith’s pitch is simple: instead of running CI workloads on rented cloud servers, companies offload them to Blacksmith’s own infrastructure. The startup owns its hardware, which it argues allows for more consistent performance than public cloud providers. That control, however, comes with operational challenges—CEO Aditya Jayaprakash told Fortune that managing capacity has become one of the company’s biggest hurdles, particularly as demand surges with new AI model releases. When Anthropic launched Claude Fable 5 in July, Blacksmith saw a sharp spike in CI workloads.

The urgency behind Blacksmith’s growth is tied to the explosion of AI-generated code. Jayaprakash wrote in a blog post that AI coding assistants have streamlined code creation, shifting the bottleneck to validation. Anthropic, for example, reported a massive increase in its code validation workload over the past six months. Blacksmith’s approach suggests that companies may prefer outsourcing this work to a specialized provider rather than handling it in-house.

That positioning places Blacksmith in a competitive but critical space. Developer tools startups have seen a surge in funding as AI reshapes software development. Just last month, Cognition raised $2 billion at a $48 billion valuation, while smaller players like ByteAsk and Town have also secured significant rounds. Blacksmith’s model—owning its infrastructure rather than relying on rented cloud capacity—could be a key differentiator, though it also faces constraints like hardware availability.

The risk for Blacksmith is that AI model providers might eventually integrate validation into their own platforms. For now, its growth suggests demand for third-party solutions remains strong. With the new funding, Blacksmith plans to expand its CI cloud and grow its team from 40 to 75 employees by the end of the year.

The next challenge will be scaling sustainably. While the company’s revenue has grown significantly, maintaining that momentum will depend on navigating supply chain constraints and competition from both cloud providers and AI-native alternatives. If successful, Blacksmith could reinforce the idea that the future of development infrastructure isn’t just about writing code—it’s about ensuring its reliability at scale.

Sources: siliconangle.com