The Surprise Hit That Made Anthropic Into an AI Juggernaut

Even Anthropic Chief Executive Officer Dario Amodei was surprised by the initial level of enthusiasm for what became the startup’s next breakthrough product. For months, engineers across the company flocked to an internal AI coding tool called Claude Code that was originally developed as a side project by Boris Cherny, then an employee in an experimental division of Anthropic that he compares to Bell Labs.

“I remember Dario asking, like, ‘Hey, are you forcing engineers to use this? Why is everyone using it?’” Cherny recalled in a recent interview. Actually, Cherny explained, all he had to do was give his co-workers access “and everyone voted with their feet.”

It was a sign of things to come. Claude Code, released publicly a year ago this month, quickly took off with software developers around the world, cementing Anthropic as a leader in a lucrative, emerging market for so-called vibe coding products. Other applications like Microsoft Copilot and Cursor were already popular with this cohort thanks to their approachable designs, but Claude Code promised to write and debug code more autonomously. Suddenly, rivals like OpenAI had to race to catch up to Anthropic, rather than the other way around.

Claude Code hit $1 billion in annualized run-rate revenue in the first six months after its release and has since grown to $2.5 billion, the company said. Once used primarily by AI-forward startups, Claude Code has gained traction with engineering teams at Fortune 500 companies and even among hobbyists lacking technical skills who are interested in building their own apps. It’s been used for everything from growing a tomato plant to helping plan the route of a NASA Mars rover. On social media, users describe themselves as “Claude-pilled,” or Claude-obsessed.

If ChatGPT’s release three-plus years ago showed the potential for generative AI to spit out clever chunks of text, Claude Code’s launch demonstrated how AI can actually perform a portion of a person’s job with limited intervention. Anthropic said some users are now letting Claude Code work autonomously on tasks for more than 45 minutes at a time before stopping it. On average, Claude Code users spend 20 hours a week working with the product.