Introduction

This talk, titled "Rails Frontend Evolution: It Was a Setup All Along" by Svyatoslav Kryukov at RailsConf 2025, explores the history and future of Rails in frontend development. The speaker traces the evolution of Rails from its early days as a full-stack framework, through periods where its frontend capabilities seemed to decline, to its current renaissance with Hotwire and Inertia.js.

Main Points

• Early Rails Era (2004 and onwards):

  • Rails introduced server-driven interactivity with Ajax helpers, enabling partial page updates without heavy JavaScript.
  • Tools like PrototypeJS and script.aculo.us offered early animation and effects capabilities.
  • RJS (Ruby-generated JavaScript) and SJR (Server-generated JavaScript responses) allowed dynamic client updates, but were limited by security and complexity.

• Rise of JavaScript Ecosystem:

  • As JavaScript frameworks grew rapidly, Rails integrated the Asset Pipeline in 3.1, allowing usage of tools like Sass and CoffeeScript.
  • Webpacker was later introduced to wrap modern JS tooling, but managing configuration complexity became a challenge.

• The API-Only Shift:

  • With Rails 5, "API mode" became standard, enabling Rails to function solely as a backend for any frontend framework.
  • Large parts of the Rails community leaned towards separating concerns, with JavaScript frontends and Rails backends.

• Three Modern Ways to Build Frontends with Rails:

  • Rails API:
  • Rails serves as a robust backend for any frontend, excelling in managing data, authentication, and business logic.
  • Emphasizes the need for good API documentation and tools like OpenAPI and Schema validators.
  • Hotwire:
  • Rails' modern HTML-over-the-wire approach leverages Turbo and Stimulus.
  • Enables fast, interactive apps with minimal JavaScript and no full page reloads.
  • Utilizes web components and import maps, fixing prior issues with lifecycle, security, and build complexity.
  • Best suited for small teams and rapid development, though complex cases may require deeper JavaScript knowledge.
  • Hybrid/Component-Based Approach (e.g., Turbo Mount & Inertia.js):
  • Integrates complex frontend components (React, Vue, Svelte) into Rails apps, offering the flexibility of modern JS ecosystems.
  • Inertia.js bridges Rails and JS frameworks by replacing the view layer, removing the need for REST APIs between frontend and backend.
  • Allows developers to benefit from both Rails and JavaScript conventions and tooling.

Examples & Illustrations

• The speaker demos early Rails Ajax helpers and mentions the evolution through RJS/SJR to Hotwire and Inertia.js.
• Describes real-world use of tools like turbo-mount and inertia-rails gem for hybrid Rails+JS applications.

Conclusion / Takeaways

• Rails' seeming retreat from the frontend was strategic: by awaiting web platform maturity, it positioned itself for a decisive return.
• Today, Rails supports multiple modern frontend strategies out of the box: API-only, Hotwire-driven server-side rendering, and hybrid/component-based approaches with tools like Inertia.js.
• The framework now embraces whatever innovations the frontend world invents, making it highly adaptable for the future.

Final Thought

"What looked like Rails losing the frontend battle was actually a strategic reinvention, positioning it at the forefront of modern web development."