Most people and companies that we talk to about upgrades assume that we generally help organizations that need to migrate to the latest Rails version.

However, this isn’t necessarily the truth. Instead, we mostly perform Rails upgrades for companies who are all the way back on Rails 3 or 4. To give you a better understanding of how common it is for companies to be on much older versions, this is a general list of our statistics from the past few years.

• Rails 2.3 - 3.2: 5 - 15 upgrades
• Rails 3.2 - 4.2: ~40 upgrades
• Rails 4.2 - 5.2: ~40 upgrades
• Rails 5.2 - 6.1: ~10 upgrades
• Rails 6.1 - 7.1: ~10 upgrades

We generally work with a lot of large, well established companies, so how did these successful companies fall so far behind, and how can you help your company to never need to hire us?

You’ve decided you need to prioritize upgrading Rails. Maybe it’s a compliance issue, you’re running a version that has reached EOL and need to upgrade to a more current one. Maybe you want to benefit from some of the new features more recent versions provide. Maybe you’ve noticed the old Rails version is getting in the way of your team’s productivity. Or maybe it’s something else.

Whatever the motivation may be, upgrading Rails can be a significant effort. As such, one of the key things to consider is how expensive will it be to get you from your current version to your target version. Regardless of whether you plan to handle the upgrade in house or outsource, how long it’ll take and, therefore, how much it’ll cost, are the key questions to answer.

We have invested more than 30,000 hours in total in upgrading Rails applications, having completed more than 100 upgrade projects. In this article, we’ll leverage our historical data and what we learned to help you answer this question: How much will this cost?

In this blog post, I detail my journey upgrading a client’s Ruby from version 2.7 to 3.0. While some of the approaches I took may be tailored to their specific needs and might not directly apply to your situation, they offer insights into one possible path for upgrading Ruby, particularly in scenarios with limited test coverage.

This article is part of our Upgrade Rails series. To see more of them, click here opens a new window .

This article will cover the most important aspects that you need to know to get your Ruby on Rails opens a new window application from version 7.0 opens a new window to version 7.1 opens a new window .

When working on upgrades, we use the Dual-Boot technique opens a new window so we can gradually update the app to work with the current version and the next one.

Eventually, the upgrade is done and the app is ready to drop the old version, but how do we handle that process? What are the steps between one upgrade and the next?

If you have ever upgraded Rails from 5.2 to 6.0 opens a new window , you might have run into issues with changes that had been made to the value of ActionDispatch::Response#content_type between the two versions.

If you have been lucky, you might not have even noticed there was a problem until Rails 6.0, after coming across this deprecation message:

Rails 6.1 will return Content-Type header without modification. If you want just the MIME type, please use `#media_type` instead.

What happened with ActionDispatch::Response#content_type between Rails 5.2 to 6.1? In this article, we will go into some background to learn what this method does, look at the differences in ActionDispatch::Response#content_type’s return value between the several Rails versions, and how you can fix the problem if you come across it in your codebase.

When you upgrade a Rails application from Rails 6.1 to 7.0, you may suddenly see a lot of changes in the schema.rb file and wonder where those changes come from and how to deal with them.

In this post, we look at what those changes are, and how to deal with them when upgrading a Rails application.

At FastRuby.io, we don’t always run rails app:update opens a new window in our process to upgrade Rails apps.

It might seem like a sacrilege - after all, that’s why the task was created, to make upgrading Rails as painless as possible, right? But we have found while upgrading dozens of applications that running rails app:update isn’t the best idea in all situations.

In this article, you will learn what rails app:update does, when it should not be used, and how to upgrade your Rails app without it.

Note: In Rails versions before 5.0, rails app:update was called rake rails:update.

If you are using the i18n gem opens a new window with Ruby 3.0 or are planning to upgrade Ruby to 3.0 while using the i18n gem, this blog post will cover a gotcha that can be tricky to understand.

We are used to checking the deprecation warnings displayed by Rails or warnings from different gems, but Ruby itself can also display warnings to help us find code that can be problematic.

In this article we will explore how to use them, how to analyze them, and some examples of interesting warnings that can be really helpful during upgrades.

When we work on Rails upgrades, most of the time we have to solve issues after updating the gems. These problems can go from simple and straightforward to really complex and hard to debug. Here we will discuss different skills and techniques that we use to complete the upgrade.

Are you considering an upgrade for your Rails or Ruby application, but you’re concerned about low test coverage? Don’t worry! In this post, we’ll explore effective strategies to address the risks associated with low test coverage. By implementing these strategies, you’ll be able to upgrade your application with confidence. Let’s dive in!

Imagine having the ability to deploy the next version of Rails in a dual booted application on your Heroku staging server or review app before deploying it to production. This capability can help you avoid bugs and downtime in your live environment. In this blog post, we will guide you on how to deploy a Rails upgrade to a staging environment, allowing you to thoroughly test it before it goes live.

There have been a lot of changes over the years in asset management opens a new window for Ruby on Rails applications. The main question, after all the madness, is… “What should I do if I need to upgrade my Rails application?”

In this article we will talk about the options we have for each version jump.

You are upgrading a Rails application. You finished fixing a deprecation warning and it’s not present anymore. You continue working on other tasks and one day you find out the deprecation is back in the codebase. New code was added using the deprecated behavior, but it was not detected and now it needs to be fixed again…

How can you prevent that from happening and, at the same time, let the team know?