Blacksmith, a startup providing infrastructure for automated software testing, has reached a valuation of $1 billion after raising $66 million in a Series C funding round led by Sequoia Capital, as the growing adoption of AI coding tools increases demand for code validation services.
The latest investment comes approximately two months after Blacksmith secured $45 million in a Series B round led by Peak XV Partners at a valuation of $550 million. The new funding brings the company's total capital raised to approximately $124.5 million.
Founded in 2024 by Aditya Jayaprakash, Blacksmith provides continuous integration (CI) infrastructure that enables software developers to build, test and validate code before deploying it into production environments.
The company's growth comes as AI-powered development tools, including OpenAI's Codex, Anthropic's Claude Code and Cursor, make it easier for developers to generate software. However, the increased volume of AI-generated code has also created additional requirements for testing and verification.
According to Blacksmith, more than 10,000 companies currently use its platform, compared with approximately 5,000 in August. Its customers include Granola, Handshake, Supabase and LangChain.
The company reported that its weekly code validation checks have increased from five million at the beginning of 2026 to approximately 90 million. Annual recurring revenue has also grown seventeenfold during the same period, according to Jayaprakash.
Blacksmith's largest customers reportedly spend more than $1 million annually on its services, while the company's overall revenue has reached tens of millions of dollars.
Unlike traditional CI providers that primarily rent computing infrastructure from cloud companies, Blacksmith operates its own servers across data centres worldwide. The company also develops software designed to reduce repetitive setup processes during testing.
Jayaprakash said the growing use of AI coding assistants has shifted development challenges from writing software to validating whether the generated code functions correctly.
The company plans to allocate most of the new funding towards expanding computing capacity to accommodate rising demand.
Blacksmith currently employs approximately 40 people across San Francisco and New York and expects to increase its workforce to around 75 by the end of 2026.
The startup also faces competition from established development platforms and AI companies introducing their own automated testing capabilities. GitHub offers hosted CI infrastructure, while AI coding platforms increasingly incorporate code review and testing functions.
According to Jayaprakash, Blacksmith's testing volumes increased by 40% following the July launch of Anthropic's Claude Fable 5 model.
The funding reflects increasing investor interest in infrastructure supporting AI-assisted software development, particularly as enterprises seek to manage the testing and deployment requirements associated with higher volumes of generated code.
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