Code testing startup Blacksmith becomes a unicorn after raising $66 million in Series C funding

Blacksmith Software Inc., a cloud continuous integration startup that helps companies test and verify new code before putting it into production, says it is now valued at $1 billion after closing a $66 million Series C funding round today.

The round was led by Sequoia Capital and included participation from Peak. It comes just two months after the company raised $45 million in a Series B round led by Peak XV. The company previously raised $10 million in September 2025.

Blacksmith was founded in 2024. The company is led by its co-founder and managing director Aditya Jayaprakash and offers a fairly novel service in the form of a “CI cloud”, where CI stands for “continuous integration”. It is the process of automating builds and tests of software before it is integrated into an existing code base and deployed in production.

Before Blacksmith, most companies handled CI themselves and ran those jobs in the cloud on servers hosted by Amazon Web Services Inc., Microsoft Azure, Google Cloud, or someone else. But these days they can instead opt for Blacksmith, which has purchased its own servers and built a dedicated CI cloud spanning multiple global locations.

The startup writes its own software to run these CI jobs. One of the main advantages is that much of the previously manual setup work required before each new piece of code can be tested can be automated.

In a blog post announcing today’s round, Jayaprakash explained that before the advent of artificial intelligence coding assistants, most developers spent about half of their time writing code and the other half waiting for it to be built and pass various tests. But with the advent of AI coding tools like Cursor, Anthropic PBC’s Claude and OpenAI Group PBC’s Codex, the process of creating new code has become “extremely easy,” he said.

“Now the bottleneck has shifted to the second part, which is: How do I actually validate all this code?” Jayaprakash told Fortune in an interview.

This phenomenon is best exemplified by Anthropic, which said last month that its code validation workload had increased more than 25-fold in the last six months because Claude took over most of the coding tasks from its human developers. Blacksmith hasn’t quite managed to solve this bottleneck, but its CI cloud relieves some of the pressure. “Enterprises bring us their CI workloads and we run them faster than anywhere else, with no operational overhead,” explained Jayaprakash.

Part of the problem with CI work is its unpredictability: demand goes from zero to tens of thousands of central processing units, then drops back to zero when testing is complete and nothing is waiting in the pipeline. Jayaprakash said his company has focused on building its cloud infrastructure to accommodate this unpredictability.

Because the company owns its own hardware rather than renting it, it has more control over its performance, allowing it to run customers’ CI workloads faster. However, Jayaprakash admitted that this is a problem for the startup as it now faces a global shortage of components such as storage.

Capacity planning has become one of the most difficult aspects of running a business, he said, as demand often spikes when a new frontier model is introduced. For example, when Anthropic introduced Claude Fable 5 in July, CI work volume increased by more than 40% in a single day.

Although Blacksmith helps companies deal with the flood of AI-generated code, there is a risk that AI model providers will become competitors and take over code validation tasks themselves.

Nevertheless, Blacksmith’s appeal cannot be denied so far. According to the startup, more than 10,000 companies now use its platform for their CI work, up from around 5,000 in August. The best-known customers include LangChain, Supabase and Granola.

At the beginning of 2026, there were approximately 5 million code reviews per week, and this number has now grown to approximately 90 million, with annual recurring revenue increasing 17x over the same period. Jayaprakash said the company’s revenue is now in the “tens of millions of dollars,” and some of its largest customers spend more than $1 million annually.

To accommodate its growing customer base, Blacksmith said it will use the majority of the money from today’s round to purchase more servers to build its global CI cloud. The company also wants to expand its team from around 40 employees to 75 by the end of the year.

Image: SiliconANGLE/Gemini