Blacksmith, a continuous integration cloud for developers, has raised a $66 million Series C led by Sequoia Capital, valuing it at $1 billion [1][2][3]. The funding follows a $45 million Series B two months earlier, led by Peak XV Partners, which valued the company at $550 million, and brings total funding to about $125 million [1][2][3]. A year ago, after a $10 million Series A, the company was valued at $60 million [1].
Blacksmith sells continuous integration: the automated build, test, and merge checks that code has to pass before it ships. Rather than rent servers from AWS, Google Cloud, or Microsoft Azure, Blacksmith owns its hardware: Jayaprakash says it has purchased tens of thousands of machines and runs a dedicated CI cloud across global data centers [2][3]. Its software handles much of the setup that used to be manually repeated for every test run [2].
The startup will use most of the new capital to purchase more computing power for that cloud [2][3]. It also intends to expand its roughly 40-person team to about 75 by year-end [2][3].
More than 10,000 companies now use its platform, up from about 5,000 in August, the company says. Its customers include LangChain, Supabase, Granola, Handshake, and Mercury [1][2][3]. The company now runs about 90 million validation checks per week, up from 5 million per week at the start of the year [2][3]; TechCrunch reported more than 90 million CI jobs run to date [1]. Annual recurring revenue grew 17 times over the same period. Jayaprakash said revenue is in the tens of millions, and its largest clients spend more than $1 million a year [2][3].
CEO Aditya Jayaprakash said AI coding tools such as Cursor, OpenAI Codex, and Anthropic Claude Code have made writing code 'extremely easy,' but validation has become the bottleneck. In a Fortune interview, he asked, 'how do I actually validate all this code?' [2][3]. In a company blog post, he wrote that the key question is 'whether it can be trusted' [1].
Anthropic said last month that its own code validation workload grew more than 25 times in six months as Claude handled most of its coding [2][3]. Blacksmith's demand is also volatile: when Anthropic launched Claude Fable 5 in July, CI volume on Blacksmith rose more than 40% in a single day [2][3]. Jayaprakash said planning for capacity is one of the toughest parts of the job, because demand jumps whenever a stronger model comes out [2][3].
Blacksmith's pitch is that customers bring their CI workloads to it, and it runs them faster than they could elsewhere with no operational overhead [2].
Sources
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Nina Castell covers startups, funding rounds and acquisitions for Venturist. She writes from company announcements, filings and published reporting.