Articles by Juan Vasquez

ERB does not know that it is generating HTML. It finds the <% %> tags, evaluates the Ruby inside them, and concatenates everything else as plain text. Whether the result is valid markup has never been its problem.

Herb changes that. On August 25, 2026, the Ruby on Rails core team merged Add Herb as an HTML-aware ERB implementation opens a new window , which brings in Herb opens a new window , an ERB implementation that parses HTML and ERB into a single syntax tree and uses Prism opens a new window for the Ruby inside the tags. Broken markup can now fail while the template compiles, instead of reaching a browser.

In this article, you will learn what Herb is, how to audit your own views with it today, what it can fix for you, what it cannot, and what it costs to run. We used the FastRuby.io views as the test subject.

Heroku sent us an email about the database behind ips.fastruby.io opens a new window , a small app we run for sharing benchmark-ips opens a new window results. That database runs Postgres 15, and the email gave it an end-of-life date on Heroku of January 20, 2027. If we do nothing before December 20, 2026, they will upgrade it to Postgres 18 for us.

Staying in control of when that happens beats finding out on Heroku’s schedule, so I upgraded it that same night. I skipped the method Heroku recommends for a documented one that suited this database better, and still finished the job with commands that are not in their documentation.

In this article, you will learn how we moved a Heroku Postgres database off a deprecated version, why we copied the data into a new database instead of upgrading in place, how much downtime to plan for, and which parts of Heroku’s tooling failed on us. We upgraded from Postgres 15 to 18, but the steps are much the same whichever version you are leaving behind.

Last weekend I migrated my Doctor’s App from Heroku to Railway.

It’s a multi-tenant Rails app where each hospital gets its own subdomain, one.doctors.com, two.doctors.com, and so on.

Five hospitals, around 25,000 appointments, 9,700+ patients. Not huge, but not trivial either.

Here’s how it went, including the part where I accidentally broke the database.

Aysan opens a new window recently wrote about accessibility testing in Rails applications opens a new window using your test suite to ensure that your application is accessible to all users.

However, you may not have a test suite in place or you may not have a Rails application, but you still want to test the accessibility of your web application, right? So, we discovered the WAVE Web Accessibility Evaluation Tools opens a new window that can help you test the accessibility of your web application, regardless of the technology stack you are using.

Does this sound interesting to you? Let’s dive in!

Did you know that we love using the Dual-Boot technique opens a new window for our Rails upgrades? We rely on the next_rails gem opens a new window to help us with dual-booting our Rails applications. This gem does more than just enable dual-booting; it also helps us identify outdated gems, check Rails compatibility, find the minimum compatible Ruby version for a target Rails version, and more.

Sounds interesting? Keep reading to learn more about the features of the next_rails gem.

Hanami opens a new window is a modern web framework which is looking for new ways to build maintainable, secure, faster and testable Ruby applications. This is a short post to show the compatibility between Hanami and Ruby opens a new window across different versions.

Is your goal to rank first on Google? Have you already tried using the best keywords and strategies to rank higher but none of that has worked? It might be because your LCP, or Largest Contentful Paint, score is high and needs improvement.

Every year, Ruby enthusiasts anticipate the December release of a new Ruby version. At the end of 2023, Ruby 3.3 was released and you can read this article opens a new window to learn more about the new features and improvements it brings. This makes it a good time to start considering if your application is due for an upgrade.

Upgrading your application can sound complicated and difficult, but it doesn’t have to be. Below, we will discuss how to identify when to upgrade your Ruby version and the steps necessary to complete a smooth and successful upgrade.

Upgrading a legacy Rails application often presents challenges, especially when migrating from Rails 4 to 5.

One significant evolution lies within the ActionController::Parameters class, Rails 5 removes the Hash inheritance which breaks application behavior. If you want to be prepared for that, keep reading this post.

Are you looking for a reliable way to test your applications? Look no further than the AAA pattern.

The AAA pattern stands for:

1. Arrange
2. Act
3. Assert

This pattern helps you structure your tests in a clear consistent manner, and it is not tied to a particular programming language or testing tool, making it a versatile and effective approach to testing opens a new window .

To automate the Ruby gem release process, we will only need to configure two things, the GitHub Actions workflow, and using conventional commit messages.

Does this sound interesting? Come and let’s dig into it.

Let’s begin with a simple question:

Have you seen config.load_defaults 6 in any application?

6 is an argument and could vary, I’m just giving an example.

I’ve always wanted to create a gem that becomes popular enough to be well known and everybody speaks about it. Unfortunately, until now it has been only a dream. In the meantime, I’ve learned how to create and release gems manually and I’d like to share that with you. Maybe somehow your gem could be the next most popular gem and I’ll be super proud of that if your first step was to read this blog post.

Deprecation warnings are a common thing in our industry. They are warnings that notify us that a specific feature (e.g. a method) will be removed soon (usually in the next minor or major opens a new window version) and should be replaced with something else. Features are deprecated rather than immediately removed, in order to provide backward compatibility (a solution that works in both the current and the future version), and to give programmers time to implement the code in a way that follows the new standard.

In this guide we’ll show you what the workflow is that we use at FastRuby.io opens a new window to address deprecation warnings when we upgrade Rails applications opens a new window .