Cutting Response Times by 78% with a Rails 7.1 Upgrade (Immigration Platform)

Rails 8 is stealing the spotlight, yet many teams are still asking the same old question:

“Is it really worth upgrading?”

For most businesses, the answer only becomes clear when security emails start piling up. When Rails 6 reached the end of its security support, that familiar tension surfaced for a US-based immigration assistance platform we recently worked with:

Keep shipping features and quietly accept the risk

or

Pause and modernize the foundation before things start breaking in production.

Their application had been running on Rails 6, which had reached the end of its security support window. With sensitive immigration data, compliance requirements, and over 70,000 families using the platform since 2017, delaying the upgrade simply wasn’t an option anymore.

The goal was straightforward: upgrade from Rails 6 to Rails 7.1. The reality, as always, was more nuanced.

Why the Upgrade Became Unavoidable

The platform relied on several gems that were no longer actively maintained on Rails 6. Libraries like rack-throttle-maintenance were showing their age, and newer versions of popular dependencies had already dropped Rails 6 support.

This created a dangerous mix:

• Known security vulnerabilities with no incoming patches
• Increasing friction when integrating modern APIs and services
• A growing risk of being locked into a brittle tech stack

For a platform handling immigration workflows, documents, and payments, that risk profile was unacceptable.

What Made This Upgrade Tricky

Before touching the Rails version, we ran a deep analysis across the codebase, infrastructure, and test setup. A few key challenges stood out.

1. Security Exposure

Rails 6 was no longer receiving critical fixes. In total, 92 security vulnerabilities were identified. For an application dealing with personal and legal data, this was a ticking clock.

2. Dependency Compatibility

Several gems were outdated or unmaintained. Some had hardcoded dependencies that didn’t play well with newer Rails versions. Replacing or refactoring around these libraries added complexity and required careful testing.

3. Zeitwerk Autoloader Issues

The project had structural problems with Zeitwerk. App constants were placed in app/ instead of lib/, which caused namespace conflicts once Rails 7’s stricter autoloading kicked in.

4. RSpec Breakages

Upgrading Rails exposed syntax and configuration issues in the test suite. Fixing these was essential to regain confidence in the system during the upgrade.

How We Approached the Upgrade

Instead of jumping directly to Rails 7.1, we took a phased, low-risk approach.

First, we upgraded from Rails 6 to Rails 7, resolved deprecations, and stabilized the application. Once things were solid, we moved forward to Rails 7.1.

This incremental strategy allowed ongoing feature development to continue without blocking the team. Over roughly three months, we balanced upgrade work with day-to-day stability, ensuring production remained unaffected.

Key Fixes Along the Way

Handling Method Deprecations

Rails 7 surfaces deprecations loudly and that’s a good thing. We systematically replaced deprecated methods with recommended alternatives before they turned into runtime failures.

Updating Critical Gems

All major dependencies were upgraded to Rails 7.1-compatible versions. Each update was validated through testing to catch subtle API changes early.

Stripe Payment Flow Stability

The Stripe gem upgrade introduced breaking changes that disrupted payment flows. After investigation, we reverted to a stable Stripe version that aligned with the existing implementation, restoring reliability without rewriting payment logic.

Fixing Zeitwerk Autoloading

We restructured the directory layout to fully comply with Zeitwerk conventions. Constants were moved to appropriate locations, resolving load errors and improving long-term maintainability.

The Results After Rails 7.1

The impact of the upgrade was immediate and measurable.

Security

Vulnerabilities dropped from 92 down to 5–10, cutting security risk by nearly 90%.

Performance

Rails 7.1 optimizations delivered noticeable gains:

• Processing time improved from 5.21s → 5.09s
• Memory usage dropped from 809MB → 692MB
• Response times improved from 957ms → 207ms

Background Jobs & Scalability

Active Job improvements, better retries, and optimized database connection pooling made background workflows more reliable and scalable under load.

Future-Proofing

The application is now compatible with modern libraries, newer Ruby versions, and evolving APIs, which, in turn, dramatically reduce future upgrade pain.

Final Thoughts

This Rails 7.1 upgrade wrapped up in about 2.5 months, with minimal disruption to users and active development. The platform is now faster, more secure, and significantly easier to maintain.

If there’s one takeaway here, it’s this: Rails upgrades don’t get easier with time. But with a phased strategy, solid testing, and a focus on real risks (not just version numbers), they can be predictable, and teams can move forward confidently without the constant overhead of security debt or upgrade anxiety.

If a Rails upgrade is on your roadmap, or you’re dealing with similar challenges around security, performance, or legacy dependencies, you can reach out to the Railsfactory team. We’re open to discussing your context and sharing what’s worked for teams like yours.