AI Code Testing Firm Blacksmith Raises $66M Series C Led by Sequoia at $1B Valuation
Blacksmith completes a $66M Series C round, reaching a $1B valuation as AI agents strain CI infrastructure.
San Francisco-based AI infrastructure company Blacksmith has announced a $66 million Series C funding round led by Sequoia Capital, with participation from Premji Invest, Peak XV Partners, GV, and Y Combinator. The round values Blacksmith at $1 billion, representing a roughly 17-fold increase from its $60 million valuation during its Series A in September 2025, and nearly double the $550 million set in its August Series B. Total funding now stands at $125 million.
Blacksmith specializes in accelerating Continuous Integration (CI), the automated building and testing of code changes proposed by developers. The proliferation of AI coding agents like Claude Code has multiplied the volume of code submissions, overwhelming traditional CI infrastructure. Anthropic noted in a September blog post that its internal CI job count rose 25-fold in six months. By running these tasks on self-managed servers rather than general-purpose cloud machines, Blacksmith claims to finish CI jobs twice as fast and at 60% lower cost.
CEO Aditya Jayaprakash stated that the funds will support hiring and computing capacity expansion. Blacksmith currently manages just under 10 megawatts across data centers in the US and Europe, with plans to grow this fivefold by 2027. While the company did not disclose absolute revenue figures, it reported that annual recurring revenue (ARR) has grown 17-fold, weekly CI jobs have surged from 5 million in January to over 90 million, and its customer base has exceeded 10,000 companies.