# Blacksmith Raises $66 Million Series C at $1 Billion Valuation, Led by Sequoia, as AI-Written Code Drives CI Demand

Times of AI Desk · 2026-10-21 · Industry

[https://timesof.ai/2026/10/blacksmith-66m-series-c-1b-valuation-sequoia-ci-cloud](https://timesof.ai/2026/10/blacksmith-66m-series-c-1b-valuation-sequoia-ci-cloud)

> 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.

## Sources

- [Blacksmith: Building the CI cloud: our Series C (October 21, 2026)](https://www.blacksmith.sh/blog/series-c)
- [Fortune: Exclusive: AI code-testing startup Blacksmith hits $1 billion valuation as AI-written code surges (October 21, 2026)](https://fortune.com/2026/10/21/exclusive-ai-code-testing-startup-blacksmith-hits-1-billion-valuation-as-ai-written-code-surges/)