Formatting an entire 25 million line codebase overnight: the rubyfmt story
Apr 28, 2026
Summary
This post details the development and rollout of rubyfmt, a Rust-based, zero-config, ultra-fast autoformatter, across Stripe's 25 million line Ruby codebase. It highlights a significant advancement in developer productivity and code standardization, demonstrating Stripe's commitment to maintaining code quality and consistency at scale, which complements the broader theme of agent-based development and infrastructure orchestration.
More from the Stripe Projects and Agent-based Development trail
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- How Stripe is designing Checkout for AI agents
- Harbor: Stripe’s AI-assisted prototyping tool
- AI didn't write our SDK. It changed how we built it.
- Reading the signals: Helping your AI-built payment integration understand business intent