How Classmethod Uses Claude Code to Cut Development Time by 90%

Japanese cloud integrators operate in a market defined by scarce engineering talent and accelerating client demand. Classmethod, one of Japan's largest AWS consulting partners, found itself caught in this squeeze: developer hours were consumed by routine coding tasks, leaving little capacity for strategic or creative work. The gap between available engineering capacity and project needs continued to widen.

Classmethod evaluated multiple AI coding tools before settling on Claude Code. The key differentiator was code quality—engineers noted that Claude Code generated significantly superior code compared to alternatives. The CLI-based interface also aligned naturally with existing developer workflows, reducing the learning curve to near zero.

The team integrated Claude Code across the full development lifecycle. It generates complete logic blocks from detailed design documents, helps engineers understand unfamiliar codebases, produces comprehensive test suites, and handles GitHub Issues-based task descriptions. The tool works across Classmethod's primary tech stack—Ruby on Rails, Next.js, and other frameworks.

The productivity gains were dramatic across multiple dimensions. Development time on specific coding tasks dropped by up to 90%. Code review time fell by 80%. One particularly striking result: a Google Apps Script task that previously took 24 hours was completed in 1 hour—a 96% reduction. Most tellingly, merged pull requests climbed from 108 in January to 165 by May and June, a sustained increase in shipped code that reflects genuine productivity improvement rather than a one-off spike.