CodeRabbit launched in late 2023 with a specific hypothesis: as AI coding tools generated more code faster, the bottleneck would shift from writing code to reviewing it. A human reviewer examining every PR in a team of 10 engineers was already a stretch; with AI-generated code, that reviewer would face a 10x volume increase. CodeRabbit’s answer was to automate the first-pass review entirely.
The tool installed as a GitHub/GitLab app and triggered automatically on every pull request, generating a readable prose summary of the changes, sequence diagrams showing how code flow had changed, and line-level comments on potential bugs, security issues, and performance concerns. A “codegraph” of the repository gave it cross-file awareness — a change to a function used in 40 other places triggered awareness of the downstream impact.
By 2026 CodeRabbit had connected 6 million repositories and served 15,000+ customers, raising a $60M Series B at a $550M valuation in September 2025. The Series B announcement explicitly cited the “vibe coding” trend as the growth driver: AI coding tools generating more PRs than human teams could review had created urgent demand for AI-assisted review. CodeRabbit’s free tier covering unlimited public and private repositories was central to its adoption strategy.