Blacksmith, the continuous integration platform built for the flood of code that AI agents now produce, announced a $66 million Series C on October 21 that values the company at $1 billion. Sequoia Capital led the round, with participation from Premji Invest and existing investors Peak XV Partners, GV and Y Combinator, taking Blacksmith’s total funding to $125 million.
The round lands just two months after Blacksmith’s $45 million Series B valued it at $550 million, and a year after a $10 million Series A at a $60 million valuation. The company says the new money will grow its team and expand the compute footprint it owns and operates for customers’ build and test workloads.
Blacksmith’s Bet: Validation, Not Writing, Is The Bottleneck
Blacksmith’s founding argument is that AI coding agents have moved the constraint in software delivery. Writing code used to be the slow part; now every change still has to be built and tested before it can merge — the continuous integration, or CI, step — and most companies run that step on general-purpose cloud infrastructure that was never designed for it, leaving teams queuing for compute on older-generation CPUs.
The company points to Anthropic’s own figures as the shape of the problem: Anthropic reported last month that its CI volume grew 25 times in six months as Claude took over most of its code output. “Since Claude Code took off in March, almost every conversation we’ve had with a large engineering team has started the same way. Developers who used to push three or four pull requests a day are now pushing orders of magnitude more and their CI infrastructure can’t keep up,” said co-founder and CEO Aditya “JP” Jayaprakash.
The Numbers Behind The Unicorn Valuation
Blacksmith says weekly CI jobs on its platform have grown from 5 million in January to more than 90 million, and annual recurring revenue has grown 17 times over the same period. More than 10,000 companies now run builds and tests on Blacksmith — TechCrunch names Mercury and Granola among customers, and the company’s own release lists Ashby, Granola, Handshake and LangChain.
Instead of renting cloud servers, Blacksmith buys its own machines and installs them in data centres, managing nearly 10 megawatts of compute across the United States and Europe, with plans to grow that footprint at least fivefold in 2027. It says customers typically see CI jobs complete twice as fast at 60% lower cost, switch with a one-line change to their workflow file, and never provision or maintain CI infrastructure themselves. LangChain infrastructure engineer Joaquin Borggio credited the platform with cutting runner costs by roughly 40% before counting saved engineering time.
Why It Matters
Blacksmith’s rise is a clean read on where value is moving as AI writes more of the world’s software: from generation to verification. The same shift is visible across this week’s startup funding — in Legora’s $550 million Series E for legal work lawyers must still check, in Pigment’s $250 million round for planning, and in Mach9’s raise for engineering drawings that still need validation.
For Blacksmith specifically, Sequoia’s backing at a billion-dollar valuation — double the August mark in two months — is a bet that owning purpose-built CI hardware beats renting general cloud capacity when demand can spike from zero to tens of thousands of CPUs and back. “As agents write more of the world’s software, the question that matters is whether it can be trusted,” Jayaprakash said. If agent-written code keeps compounding, the companies that test it become infrastructure, and infrastructure is where the durable money sits.
Background
Blacksmith was founded in 2024 by Jayaprakash, Aayush Shah and Aditya Maru, who met as undergraduates at the University of Waterloo; Shah and Maru were early engineers at Cockroach Labs and Jayaprakash engineered at Faire. The three built the company on the view that testing code, not writing it, would become the constraint on shipping software — a view the Claude Code era has since made mainstream, and one Sequoia partner Isaiah Boone credited in the round announcement, citing the team’s systems expertise and speed of execution.
Source: Blacksmith via PR Newswire, TechCrunch
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