Ruby Patterns

This file extends common/patterns.md with Ruby and Rails specific content.

Rails Way First

• Start with plain Rails MVC and Active Record conventions for small and medium features.
• Introduce service objects, query objects, form objects, decorators, or presenters when the model/controller boundary is carrying multiple responsibilities.
• Name extracted objects after the business operation they perform, not after generic layers like Manager or Processor.

Persistence

• Prefer PostgreSQL for multi-host production Rails apps unless the existing platform has a clear reason for MySQL or SQLite.
• Treat Rails 8 SQLite-backed defaults as viable for single-host or modest deployments, not as an automatic fit for shared multi-service systems.
• Keep raw SQL behind query objects or model scopes and parameterize every dynamic value.

Background Jobs And Runtime Services

• Use Solid Queue for greenfield Rails 8 apps with modest throughput and simple deployment needs.
• Use Sidekiq when the app needs mature observability, high throughput, existing Redis infrastructure, or Pro/Enterprise features.
• Use Solid Cache and Solid Cable when their deployment model matches the app; use Redis when shared cross-service behavior, high fanout, or advanced data structures matter.

Frontend

• Prefer Hotwire with Turbo, Stimulus, Importmap, and Propshaft for server-rendered Rails apps.
• Use React, Vue, Inertia.js, or a separate SPA when interaction complexity, existing product architecture, or team ownership justifies the extra client surface.
• Keep view components, partials, and presenters focused on rendering decisions; keep persistence and authorization out of templates.

Authentication

• Use the Rails 8 authentication generator for straightforward session auth and password reset needs.
• Use Devise or another established auth system when requirements include OAuth, MFA, confirmable/lockable flows, multi-model auth, or a large existing Devise footprint.

Reference

See skill: backend-patterns for service boundaries and adapter patterns.