Rakuten - Japan's largest e-commerce platform, with over 70 million loyalty program members and more than 70 services running under its umbrella - has published a case study with Anthropic describing how its engineers adopted Claude Code to speed up software development.
Claude Code is Anthropic's command-line coding assistant. Unlike chat-based coding helpers, it operates directly in a terminal and can read files across an entire project, write and edit code, run tests, and commit changes without copy-pasting between windows. For a company like Rakuten, which runs shopping, banking, travel, and streaming services on infrastructure built across decades, the codebase complexity is substantial.
What Rakuten Used It For
According to Anthropic's customer story, Rakuten engineers used Claude Code for code review, documentation, and working through accumulated technical debt - the unglamorous, time-consuming work that slows teams down. The case study describes accelerated development cycles but does not include specific time or productivity metrics.
Rakuten joins Stripe, Cloudflare, and others that have published public endorsements of Claude Code. What distinguishes this case study is the combination of scale and legacy complexity. New startups on modern stacks are relatively easy wins for AI coding tools. Enterprise systems with older code, multiple programming languages, and years of accumulated workarounds are a much harder test.
How Claude Code Compares to Cursor and Copilot
Claude Code's main advantage for large codebases is its 200,000-token context window (roughly 550 pages of text at once), which lets it reason about substantial chunks of a project simultaneously. Cursor, a competing AI coding tool, has a more polished IDE interface but similar context constraints. GitHub Copilot integrates more tightly with existing workflows but is better suited for autocomplete than for navigating complex legacy projects.
Enterprise case studies like this confirm Claude Code can work at scale - they don't confirm it'll work on your specific stack. Anthropic's standalone Claude Code plan runs $100 per month per user. Enterprise pricing is negotiated separately.