As AI dramatically accelerates the pace of code generation, a new bottleneck has emerged in software development: validating and testing all that code before it reaches production. Blacksmith, a startup building AI-powered testing and validation tools, has raised a new $45 million round to capitalize on this shift.
The Series B was led by Peak XV Partners, an investor known for backing ambitious technology companies across the globe. The round values Blacksmith at $550 million, a sharp increase from the $60 million valuation it received when it raised a $10 million Series A less than a year ago. Existing investors GV and Y Combinator also participated, helping bring the company's total funding to $58.5 million.
Blacksmith was founded in 2024 with a simple mission: help companies build, test, and verify software more effectively before it goes live. The startup has quickly attracted a wide range of customers, from fast-growing startups to established technology firms. Today, Blacksmith says it serves more than 5,000 customers, including Mercury, Supabase, Clerk, Ashby, and Expensify. That number stood at just over 700 customers less than a year ago, representing a remarkable surge in adoption.
The AI coding boom and the validation problem
The rise of AI-powered coding tools such as Cursor, OpenAI's Codex, and Anthropic's Claude Code has made it significantly easier for software teams to generate code. Developers can now produce entire functions, modules, and even complete applications with minimal effort. However, the ease of generation has introduced a new challenge: ensuring that the code is correct, secure, and reliable.
Aditya Jayaprakash, co-founder and CEO of Blacksmith, says that validation has become the industry's biggest pain point. “Validating code is still a bottleneck, and it's an even bigger bottleneck because people are writing even more,” he said in an exclusive interview. The explosion in code volume means traditional testing approaches are no longer sufficient. Teams need faster, smarter ways to run tests, identify failures, and fix issues before they affect end users.
Blacksmith started as a cloud provider for continuous integration (CI) workloads. CI is a development practice where code changes are automatically built and tested every time a developer commits code. This process helps catch bugs early, but it can be slow and expensive, especially for teams generating large amounts of AI-assisted code. Blacksmith's platform was designed to make CI faster and more affordable, allowing companies to run the builds and tests needed to validate code without waiting for lengthy queues.
Expanding beyond CI with Codesmith
Recognizing that simply running tests faster was not enough, Blacksmith broadened its platform with an AI coding agent called Codesmith. This agent is designed to automatically fix failed code checks, reducing the manual effort developers need to spend on debugging. When a test fails, Codesmith analyzes the issue, identifies likely causes, and proposes or applies fixes. This capability is especially valuable in an AI-driven development environment, where code is generated quickly but may contain subtle errors.
The combination of fast CI infrastructure and AI-powered repair has resonated with customers. Jayaprakash noted that Blacksmith reached a $10 million annualized revenue run rate with just 10 employees, a remarkable achievement for such a young company. Since then, the workforce has grown to about 30 employees, and revenue has climbed to “tens of millions of dollars.” He declined to provide a specific updated ARR figure, though he did say some of its largest customers now spend more than $1 million a year on the platform.
The competitive landscape
Blacksmith is not alone in pursuing this opportunity. The market for AI-aware testing and validation is becoming increasingly crowded. Key competitors include GitHub Actions, which is widely used for CI/CD workflows, and Cursor Automations, which brings agentic coding capabilities directly into the popular editor. Validation capabilities are also being baked into AI coding tools like OpenAI's Codex and Anthropic's Claude Code, allowing developers to run tests and receive feedback without leaving their development environment.
In addition to these dedicated tools, large cloud providers are entering the space. Amazon Web Services, Microsoft Azure, and Google Cloud all offer AI-powered testing services that integrate with their broader developer platforms. Numerous other startups are also vying for a share of the market, each with a slightly different approach to the problem.
Despite this intense competition, Jayaprakash says Blacksmith is carving out a distinct position by focusing on two key differentiators: speed and affordability. Faster CI pipelines mean developers can get feedback in minutes rather than hours, which is crucial when AI is generating code at scale. Affordability is equally important, as teams that rely heavily on AI code generation may run thousands of tests daily, and cost can quickly become prohibitive.
Market context and investor confidence
The funding round comes at a time when investor interest in AI infrastructure and developer tools remains strong. As AI assistants become more capable, the software industry is grappling with how to manage the resulting flood of code, security risks, and quality concerns. Blacksmith's rapid growth suggests that companies are willing to pay for solutions that address these issues head-on.
Peak XV Partners, which led the Series B, has a strong track record of backing enterprise and developer-focused startups. The firm's decision to lead a round at a valuation of $550 million, less than a year after Blacksmith was valued at just $60 million, signals confidence in the company's execution and market opportunity. GV, formerly Google Ventures, and Y Combinator, where Blacksmith was likely incubated, also renewed their support. Y Combinator's continued participation highlights the startup's potential to become a major player in the developer tools ecosystem.
The broader CI/CD market has grown steadily over the past decade, but AI has supercharged the need for faster, more intelligent testing. According to industry analysts, the rise of AI-generated code is expected to multiply the number of software builds and tests that organizations need to run. This creates a significant tailwind for companies like Blacksmith that provide the infrastructure and tools to handle the increased load.
Customer adoption and real-world use cases
Blacksmith's customer list includes a mix of well-known names and emerging companies. Mercury, a banking platform for startups, likely uses Blacksmith to ensure its financial software remains reliable. Supabase, an open-source Firebase alternative, builds and tests large amounts of code and needs fast CI to keep up with its open-source community. Clerk, which provides authentication tools, and Ashby, an applicant tracking system, also require robust testing to maintain high-quality products. Expensify, a long-standing expense management company, has integrated the platform into its software development lifecycle.
The fact that Blacksmith has grown its customer base from 700 to more than 5,000 in under a year suggests strong product-market fit. Many of these customers are probably smaller startups looking for affordable CI solutions, but the presence of large spenders indicates that the platform can scale to enterprise needs as well. The company's ability to retain and expand accounts will be critical as it faces increasing competition from tech giants and other startups.
Future plans and broader ambitions
Looking ahead, Blacksmith plans to expand into a broader suite of coding tools, aiming to help developers not just test code but also write and merge it faster. Jayaprakash envisions a platform that covers the entire software delivery lifecycle, from initial code generation to production deployment. This would bring Blacksmith into direct competition with larger development platforms, but the company believes its deep focus on testing and validation gives it an edge.
The startup is likely to invest heavily in Codesmith and other AI capabilities. As large language models improve, these agents will become better at understanding codebases, anticipating failures, and suggesting fixes. Blacksmith may also add features such as security scanning, performance testing, and deployment verification to provide a complete suite of tools for modern software teams.
With its new funding and growing customer base, Blacksmith is well-positioned to become a key player in the AI-driven software development ecosystem. The challenge of validating code is not going away, and as more organizations adopt AI coding tools, the need for reliable testing infrastructure will only increase. Blacksmith's rapid rise demonstrates that even in a crowded market, a focused approach can yield impressive results.
Source: TechCrunch News