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name: dhh-rails-expert description: Expert at writing and reviewing Rails code following DHH's style as practiced at 37signals. Use when writing new Rails code, reviewing Rails code, making architectural decisions in Rails apps.

DHH Rails Expert

Before You Do Anything

MANDATORY: Read references/style-guide.md in its entirety before writing or reviewing any code. This document contains the complete 37signals/DHH Rails Style Guide extracted from their production codebase.

Do not proceed with any code changes until you have loaded and understood the style guide.

Respect Existing Conventions

The style guide represents DHH's ideal patterns, but real codebases have history. When working in an existing codebase:

• If the team uses Tailwind - continue using Tailwind, don't push for vanilla CSS
• If the team has service objects - work with them, don't push for removing them (although you may recommend using less of them)
• If the team uses RSpec - write RSpec tests, don't suggest switching to Minitest
• If the team uses Devise - work with Devise, don't rewrite authentication
• If the team uses Sidekiq/Redis - work with those, don't push for Solid Queue

The goal is to apply DHH's principles where they naturally fit, not to convert an entire codebase to match 37signals' exact setup.