Blacksmith's jobs grew 18x. Its valuation grew 1.8x, and GitHub controls the gate

Sequoia values Blacksmith at $1 billion, only 1.8 times its March price, while weekly jobs rose 18 times. GitHub's postponed fee and a lagging compute plan cap the upside.

Sequoia Capital has put a $1 billion valuation on a company that runs other people's software builds. Blacksmith announced a $66 million Series C on Wednesday. Premji Invest joined, while Peak XV Partners, GV and Y Combinator returned. Total funding now stands at $125 million.

Usage has compounded about ten times faster than the price. Jobs grew 18 times this year; the valuation rose 1.8 times.

Investors are paying for a chance to own the layer that checks machine-written code. GitHub controls the system Blacksmith plugs into, and demand is outrunning the compute plan.

Blacksmith's chief executive says in a post on the round that weekly jobs rose from 5 million in January to more than 90 million. These are continuous integration (CI) jobs. CI is the automated building and testing that every code change must pass before it merges. Annual recurring revenue, or ARR, is up 17 times, and Sequoia's own note repeats both figures.

The last mark was $550 million, from a Series B that Blacksmith raised in March and announced on 12 August. Against that, $1 billion is a step of 1.8 times in about seven months.

Revenue is growing far faster than the price. ARR is up 17 times since January, while the price is up 1.8 times since March. Blacksmith's chief executive told Fortune that revenue is now in the tens of millions of dollars. Even at $90 million, near the top of that range, $1 billion is about 11 times revenue. Sequoia adds that the largest customers now spend more than $1 million a year.

Revenue per job is about level. ARR rose 17 times and jobs rose 18 times, so each job earns roughly what it did in January. A company with pricing power would show revenue per job rising.

Jobs are growing about as fast as the company said in August. The Series B post claimed 5 to 10 percent growth a week. Eighteen times over 42 weeks compounds at 7.1 percent a week, inside that range.

Customers show the same pull. The Series B post cited more than 6,000 companies. Sequoia now cites more than 10,000, up from 700 a year ago.

Coding agents explain much of the volume, because every machine-written change must be built and tested before it merges. Anthropic reported in September that its own CI job volume rose 25 times in six months. That is the traffic Blacksmith sells capacity into. Blacksmith's customers describe the same squeeze. One quoted in the Series B post says pull request volume rose 4 times after its developers adopted Claude Code, and its CI could not keep up.

GitHub owns the front door to Blacksmith's product. The homepage describes a drop in replacement that costs 60 percent less than GitHub runners, the machines that execute each job. The switch is one edited line in a workflow file, from ubuntu latest to a Blacksmith machine name.

That line works only because the job still starts in GitHub Actions. Whoever owns that system controls the gate.

Blacksmith is adding products beyond renting machines. It has launched a cloud coding agent and plans a QA tool that tests changes before they merge. This is the validation layer a $1 billion price points to.

GitHub has already shown how it might charge. Its December notice added a $0.002 a minute platform charge on Actions. On GitHub hosted runners it took effect on 1 January, folded into a net price cut of up to 39 percent.

The charge on self hosted runners, due 1 March, was postponed while GitHub rethinks its approach. A self hosted runner is a machine that someone other than GitHub operates. A third party runner such as Blacksmith's sits in that group. GitHub's billing page still lists self hosted usage as free, so the toll is a threat, not yet a charge.

Blacksmith's saving is an average. The company claims jobs finish twice as fast at 60 percent lower cost. LangChain, its named customer, says its runner costs fell about 40 percent.

GitHub controls both levers that set that saving. A cheaper hosted price narrows the gap directly. A fee on self hosted runners narrows it from the other side.

Model vendors are the other threat. Codex and Claude Code already run a project's tests as they work. Cursor launched a product in March that sets up agents to review and test new code. The chief executive replies that better models mean more code to check. He says job volume rose 40 percent when Anthropic launched a new model in July.

Capacity is the second constraint, and it is the weaker part of the plan. Blacksmith runs just under 10 megawatts of compute in the United States and Europe and plans to grow that at least fivefold in 2027. In August it promised a tenfold jump within months, counted in cores.

Demand is on course to outrun that build. If each job needs about the same compute, even 4 percent weekly growth turns 90 million jobs into 7.7 times that over a year, more than a fivefold build. Jobs have grown about 7 percent a week all year.

Capacity will decide how the $1 billion looks. If jobs grow even 4 percent a week, 90 million become about 180 million by late February 2027. Blacksmith plans to reach five times today's footprint only by the end of 2027. By then it will either have built ahead of that plan or have customers waiting. That will say more about the price than the round did.