Java Tech Enthusiast

Jul 21, 2026 · Artificial Intelligence

Migrating Millions of Lines of Code with Claude Code: A Step‑by‑Step Guide

The article analyzes Anthropic's Claude Code workflow for massive code migrations, detailing two real‑world cases—a 530k‑line Bun rewrite from Zig to Rust in 11 days and a 165k‑line Python‑to‑TypeScript conversion over a weekend—then breaks down the six‑step process, rule‑book creation, adversarial review, and practical cost considerations.