Running an older version of Rails is a liability. Security patches stop. Gems drop support. New hires don't want to work on Rails 4. Every month you wait, the upgrade gets harder.
We upgrade Rails applications for a living. Rails 4 through Rails 8, one major version at a time, with the test suite green at every step. No big-bang rewrites. No surprises on deploy day. We've done this enough times to know where the problems hide, and we fix them before they reach production.
0-4 yrs
0-4 yrs
20%
20%
5
5
100+
100+
Upgrade Services
Every upgrade follows the same discipline. We go one major version at a time. Rails 4 to 5, then 5 to 6, then 6 to 7, then 7 to 8. Skipping versions causes problems that are harder to debug than the upgrade itself.
Before we touch your code, we audit the full dependency tree: which gems have compatible versions, which need replacements, and which custom patches exist in your codebase. We set up a parallel test environment so the upgrade never touches production until every test passes.
Comprehensive Ruby on Rails Upgrade Expertise
Upgrade Services
Every upgrade follows the same discipline. We go one major version at a time. Rails 4 to 5, then 5 to 6, then 6 to 7, then 7 to 8. Skipping versions causes problems that are harder to debug than the upgrade itself.Before we touch your code, we audit the full dependency tree: which gems have compatible versions, which need replacements, and which custom patches exist in your codebase. We set up a parallel test environment so the upgrade never touches production until every test passes.
Rails Version Upgrades
Moving from any Rails version to the latest stable release. We go one major version at a time. Each step gets its own branch, its own test run, and its own deploy. If something breaks at Rails 6 to 7, we fix it there instead of carrying the problem forward.
Ruby Version Upgrades
Ruby and Rails versions are coupled. An upgrade to Rails 7 often requires Ruby 3.1+. We handle both together: Ruby version bump, syntax changes, frozen string literal adjustments, and any C extension compatibility issues with native gems.
Gem Dependency Resolution
The hardest part of most upgrades isn't Rails itself. It's the 80+ gems in your Gemfile. Some need version bumps. Some have been abandoned and need replacements. Some have forked. We resolve every dependency conflict and test each replacement before it goes into your codebase.
Legacy Code Modernization
Deprecated methods, removed APIs, and old patterns that worked in Rails 4 but break in Rails 7. We refactor the code to use current Rails conventions: Strong Parameters instead of attr_accessible, Active Storage instead of Paperclip, Action Mailbox instead of custom email parsing. Your codebase comes out cleaner, not just newer.
faqs
Everything you need to know before getting started with us. Below are out most common questions we get asked.
How do you handle a Rails upgrade for an app with low test coverage?
We write the critical tests first. Before touching any Rails version, we add test coverage for authentication, payment flows, data mutations, and core business logic. These are the paths where a silent failure costs you the most. Once the safety net is in place, we start the version migration. The test-writing phase usually adds 1-2 weeks to the project, but it's non-negotiable. Upgrading without tests is gambling with your production data.
What's the difference between upgrading Rails and upgrading Ruby?
They're related but separate. Rails depends on specific Ruby versions. Rails 7.0 requires Ruby 2.7+, Rails 7.1 needs Ruby 3.0+, and Rails 8 needs Ruby 3.2+. We upgrade both together in the correct order: Ruby first (if needed), then Rails. Ruby upgrades involve syntax changes, frozen string literal defaults, and native gem recompilation. Rails upgrades involve framework API changes, gem compatibility, and configuration updates.
Can you upgrade a Rails 4 or Rails 5 app directly to Rails 8?
Not directly, and anyone who says they can is cutting corners. We go one major version at a time: 4 to 5, then 5 to 6, then 6 to 7, then 7 to 8. Each step has its own set of deprecations, gem changes, and configuration shifts. Skipping versions means stacking problems on top of each other, which makes debugging nearly impossible. The version-by-version approach takes longer on paper but is faster in practice because you're never debugging four migrations at once.
How long does a typical Rails upgrade take?
A single major version jump (e.g., Rails 6 to 7) on a well-tested app with 50-80 gems typically takes 2-4 weeks. A multi-version jump (Rails 4 to 8) can take 2-3 months because each version is a separate migration. The biggest variables are test coverage (low coverage means we write tests first), gem count (more gems means more compatibility work), and custom monkey patches on Rails internals. We scope every upgrade before quoting so you know the timeline upfront.
Will my app have downtime during the upgrade?
No. The entire upgrade happens on a separate branch. Your production app runs untouched on the current version while we build and test the upgraded version in a staging environment. When everything passes, the deploy to production is a standard deployment with zero downtime. If something unexpected happens, we roll back immediately. Your users never see a broken app.
What happens to gems that don't support the new Rails version?
Three options. First, we check if a newer version of the gem exists that's compatible. That's the easy case. Second, if the gem is abandoned, we find a maintained alternative that does the same thing and migrate your code to it. Third, if no alternative exists and the gem is critical, we fork it and patch it ourselves for compatibility. We document every gem change so your team knows exactly what was replaced and why.
Should we upgrade to Rails 8 or stay on Rails 7?
If you're on Rails 7.1 or 7.2, Rails 7 still receives security patches, so the upgrade isn't urgent. But Rails 8 brings Solid Queue (background jobs without Redis), Solid Cache (database-backed caching), Kamal for deployments, and authentication generator built in. If you're starting a new feature cycle or your infrastructure would benefit from fewer dependencies, Rails 8 is worth the move. If you're on Rails 6 or older, upgrade to 7 first, then evaluate 8.
Why hire an upgrade agency instead of doing it in-house?
Your team knows your business logic. We know Rails migrations. An in-house upgrade means your developers spend weeks fighting gem compatibility, deprecation warnings, and CI configuration instead of building features. We've done hundreds of version migrations, which means we know which gems cause problems, which deprecations have non-obvious fixes, and where the hidden breaking changes are. Your team stays productive on feature work while we handle the upgrade. Most clients find it's faster and cheaper than pulling their own developers off the roadmap.