Ruby on Rails

Ruby on Rails (or just Rails) is a server-side web framework written in Ruby and released in 2004. Rails popularised the "convention over configuration" philosophy, the MVC pattern in web frameworks, and the idea that one developer could build a complete production application in days. GitHub, Shopify, Basecamp, and many SaaS products are built on Rails.

Core pieces

• Active Record. The ORM that maps Ruby classes to database tables with rich query and association APIs.
• Action Controller. Handles HTTP requests, parameter binding, filters, and rendering.
• Action View. ERB or HAML templates for HTML rendering.
• Active Job. Background job abstraction with adapters for Sidekiq, Resque, GoodJob.
• Action Mailer, Action Cable, Active Storage. Built-in email, WebSockets, and file attachment subsystems.
• Hotwire. Turbo and Stimulus for building reactive interfaces with minimal JavaScript.

Notable conventions

• Database migrations live in the codebase and are versioned in Git.
• Routes are defined declaratively in config/routes.rb.
• Convention over configuration: controllers, models, and views follow naming rules so wiring is automatic.