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Maintaining a Ruby on Rails application often slips down the priority list. Everything seems fine, until suddenly it isn’t. A gem update breaks a feature, a security flaw makes headlines, or your app refuses to deploy after a server upgrade. When that happens, teams scramble to find help, often at the worst possible time. This “as-needed” upgrading approach may appear cost-effective in the short term, but it leads to stress, downtime, and unpredictable expenses.

But there is a smarter path forward: fixed-cost monthly maintenance opens a new window . In this post, you’ll see why investing in a maintenance retainer is better than reactive upgrades, and how our service delivers value month after month.

Ruby on Rails has always moved at a steady, thoughtful pace: each new version brings not only features and performance improvements but also important security hardening. But with every release cycle, older versions reach the end of their lifespan. When a version is officially End-of-Life (EOL), it no longer receives bug fixes or security patches — leaving applications increasingly vulnerable as new threats emerge.

Ruby 3.4.0 was released on December 25, 2024, bringing exciting new features, performance improvements, and some breaking changes. Here’s a practical guide of what’s new and what you should know before upgrading to this version.

Highlights

• New it block parameter reference: Cleaner, more readable blocks using it instead of the original _1.
• Language and core changes: Easier keyword argument handling, string literal warnings, reserved names, and updates to core classes.
• Standard library updates: RubyGems, Bundler, JSON, Tempfile, and more get useful updates.
• Compatibility and miscellaneous changes: New error message formats, hash and float handling, block and performance warnings, and deprecated features removed.
• Prism is now the default parser: Ruby’s parser is now Prism, making it possible for better tooling and error messages.
• Socket library upgrade: Happy Eyeballs v2 means faster, more reliable network connections out of the box.
• YJIT and Modular GC: Advanced performance and memory improvements for those using Ruby’s JIT or experimenting with garbage collection.

Rails 7.1 has been a dependable workhorse since its release in 2023. But on October 1, 2025, Rails 7.1.x will lose official security support opens a new window . That means no more patches for new vulnerabilities, no more backports, and no safety net if a zero-day exploit lands in your stack.

If you’re running Rails 7.1, your risk level depends heavily on which Ruby version you pair it with. Some Rails and Ruby combinations will be doubly unsupported after October 1st, creating “dangerous pairings” that should be upgraded immediately.

In this post, we’ll break down:

• Which Ruby on Rails setups will lose support after October 1, 2025.
• Why those combinations are risky.
• How to quickly check your environment using our table below.
• What to do if you are using a vulnerable pair.

Ruby 3.2, released in December 2022, introduced the Data class. A built-in, immutable value object for Rubyists who want simple, safe, and fast data structures without the boilerplate of custom classes or Structs. If you haven’t upgraded to Ruby 3.2 or later, you’re missing out on this powerful feature!

The Roadmap to Upgrade Rails opens a new window is FastRuby.io’s discovery product that helps teams plan and execute their Rails upgrade projects.

We’re happy to introduce an Automated Version of the Roadmap, powered by an AI agent, available completely for free!

Check it out on the Automated Roadmap to Upgrade Rails opens a new window page and keep reading to learn more about how it works.

At FastRuby.io, we spend our days deep in Rails codebases, upgrading, refactoring, and occasionally wondering, “Wait… is this method from Ruby or Rails?”.

Now, we’re turning that moment of confusion into a game. We’re excited to introduce Is It Ruby or Rails?, a brand new Discord bot that delivers daily puzzles to challenge your Ruby knowledge and fuel a little friendly competition.

You can install it using the Discord install link opens a new window and start playing right away!

At our company, we believe the tools we use should reflect our values: simplicity, speed, and transparency. That’s why we use Jekyll opens a new window , a static site generator built in Ruby, to power our blog.

While there are countless blogging platforms and content management systems available today, from WordPress to headless CMS options, we chose Jekyll because it gives us full control, minimal complexity, and a workflow that fits seamlessly into how we already work as developers.

Here’s why we think it’s the right fit for us (and maybe for you too):

When people hear the phrase “technical debt”, they often picture broken code, outdated infrastructure, or a total rewrite waiting to happen. But in our experience at Planet Argon opens a new window , technical debt usually shows up more quietly.

It’s not a crisis. It’s a pattern.

It shows up in how long it takes to make changes, how often bugs sneak in, and how hesitant developers are to touch certain parts of the codebase. And while it rarely announces itself, it always costs something — whether in time, budget, or momentum.

In this post, we’ll highlight real-world examples of how technical debt has surfaced in Rails applications we’ve worked on. These aren’t horror stories — they’re common issues we see even in well-run projects. More importantly, we’ll share some ways teams can manage debt strategically without a massive rewrite.

At FastRuby.io opens a new window , we deeply value the Ruby and Rails communities and believe in giving back through open source contributions. We wouldn’t be where we are today if it wasn’t thanks to a lot of open source projects we use on a daily basis.

We actively use, maintain, and enhance several tools designed to empower developers and teams who want to handle Ruby and Rails upgrades themselves, especially those who might not have the budget to hire our services.

These open source projects facilitate upgrades by improving transparency, managing technical debt, and ensuring smooth transitions between Ruby and Rails versions.

Here’s an overview of each tool and how it can support your next upgrade project.

Whether you’re debugging a dependency issue, checking for an optional gem, or just curious about what’s loaded in your Ruby app, there’s a handy command that can help:

puts Gem.loaded_specs.keys.grep(/your_pattern_here/)

In this article, we will discuss what this command does, what exactly it’s checking for, and its limitations.

At FastRuby.io opens a new window , we offer specialized Rails upgrade, maintenance, and technical debt services.

Before doing an upgrade, we strongly recommend doing the Roadmap to Upgrade Rails opens a new window , a static analysis of your codebase that outlines the action plan to do the upgrade and provides time and investment estimates.

The first step in every Rails upgrade we do is addressing deprecation warnings in the current version. So recently, we set out to extract all deprecation warnings from all versions of Rails starting at Rails 2.3 to help in our static analysis of Rails applications.

Having reproducible development environments is one of the best ways to guarantee ease of application setup and code sharing in teams. Dev containers are a way to achieve this.

In this article we’ll try to give you a small introduction to what dev containers are at their core and provide a minimal example on how to set up a Rails application to use dev containers.

In this article we will present compatibility between Ruby opens a new window and Heroku opens a new window across different versions. In the process of upgrading really old applications to more modern versions of Ruby we have run into a lot of these combinations.

In Ruby, we often want to rename methods or attributes for clarity, to extend functionality and for compatibility. However, there are three different tools for this, each with its own use case and behavior: alias, alias_method and alias_attribute.

In this post we’ll go over each one of them, what they actually do and when to use them.