Anthropic went from a respected safety lab to a company with a $47 billion revenue run-rate in about eighteen months, and the hinge was Claude Code, which found its audience inside VS Code, the editor Microsoft gives away for free. Stack Overflow's 2025 Developer Survey put VS Code at 75.9% usage among development environments, and Microsoft told investors that Visual Studio and VS Code together had more than 50 million monthly active users. Boris Cherny, a former Meta engineer who now heads Claude Code at Anthropic, joined the company in September 2024, starting with terminal experiments. By November, more than half of Anthropic's own engineers were using the tool every day. Anthropic launched Claude Code publicly in February 2025 alongside Claude 3.7 Sonnet as a command-line tool. On September 29, 2025, as part of the Claude Code 2.0 release, it shipped a native VS Code extension, bringing Claude Code directly into the IDE with a sidebar panel and real-time inline diffs.