Upgrade & Optimize
Your Rails app is
slowing you down.
Let's fix that.
Ruby on Rails upgrade services for production apps. We take you from Rails 5, 6 or 7 to Rails 8 one version at a time, with test coverage added first and zero downtime on deploy.
No rewrite, no feature freeze. Outdated versions, AI-generated code and slowing performance are solvable problems, and we have solved them on more than 100 production Rails apps.
Two Services, One Team
Upgrade your Rails version
or fix what AI wrote
Two distinct problems, both costing you velocity. We handle them with the same rigor: systematic analysis, clear plan, verified execution.
Track A
Rails Version Upgrade
Running Rails 5 or 6 in 2026 is a security liability and a hiring problem. We upgrade your application to Rails 8 version by version: safely, with full test coverage, and zero downtime on deployment.
1
Dependency Audit
We map every gem, identify incompatibilities, and quantify the full upgrade scope before writing a line of code.
2
Test Suite Baseline
If coverage is thin, we expand it first. You can't safely upgrade what you can't verify.
3
Version-by-Version Upgrade
We upgrade one minor version at a time with a full green test suite at each step. No skipping, no shortcuts.
4
Framework Defaults
We run
app:update, review every generated diff, and apply new configurations safely, with no unexpected behavior.5
Zero-Downtime Deployment
Staged rollout through your existing pipeline. We stay on-call through go-live and monitor for regressions.
Track B
AI Code Fix
AI-generated code can get you to 80%. The other 20% is hidden bugs, missing tests, security gaps, and architectural blind spots, and that is what we fix before it costs you in production.
1
Full Code Audit
We review every AI-generated file for correctness, security, and architectural fit within your existing application.
2
Refactoring
We rewrite the problematic sections rather than patch them. Clean, idiomatic Rails code that your team can maintain.
3
Test Coverage
Every fixed component gets unit and integration tests. CI integration so regressions never reach production again.
4
Security Hardening
We remediate auth issues, injection risks, hardcoded secrets, and outdated gems identified during the audit.
5
Architectural Review
We align the AI-generated code with your application's existing patterns and document decisions for your team.
Why It Matters
Every version behind
costs you more
An outdated Rails version is a compounding liability. It touches security, performance, hiring, and developer productivity every day you don't address it.
🔒
Security Vulnerabilities
Older Rails versions have known, public CVEs. Running them in production is an active risk, not a theoretical one. Every patch release you've missed is a potential attack vector.
🐌
Performance Left on the Table
Each Rails major release brings meaningful performance improvements. Apps on Rails 5 or 6 are leaving measurable response time and memory efficiency gains unclaimed.
👩💻
Hiring Gets Harder
Senior Rails engineers don't want to work on legacy codebases. An outdated stack narrows your hiring pool and signals technical dysfunction to candidates.
📦
Gem Compatibility Breaks
The Rails ecosystem moves forward. Gems drop support for old versions, forcing you to freeze dependencies or fork, both of which compound your technical debt faster.
🤖
AI Code Creates New Risk
AI-generated code is fast but context-blind. It doesn't know your architecture, your security requirements, or your scaling constraints. Unreviewed, it introduces subtle problems that surface in production.
⏱
The Longer You Wait
A Rails 6 to 8 upgrade today is a defined project. A Rails 4 to 8 upgrade in two years is a near-rewrite. The gap compounds. The right time to upgrade is always now.
AI Code Reality
Functional isn't the
same as production-ready
AI tools accelerate development significantly. But they generate code that works in isolation, without knowledge of your application's architecture, performance requirements, or security posture. Here's what we find in AI-generated Rails code every week.
✗
N+1 queries no one noticed
AI generates associations without eager loading. Works fine in tests with 10 records. Falls over in production with 10,000.
✗
Context-blind architecture
Code that works standalone but violates your existing patterns, creating maintenance debt from the first merge.
✗
Missing authentication & authorization
AI generates happy-path code. Auth edge cases (mass assignment, missing before_actions, insecure direct object references) don't make it into the prompt.
✗
Zero test coverage
AI writes code, not tests. Untested AI code merges silently and creates a floor below which quality can only fall.
✗
Hardcoded values & credentials
Secrets in source, magic numbers in logic, environment-specific values hardcoded. Common in AI output, dangerous in production.
N+1 Query Fix
- def index
- @orders = Order.all
+ def index
+ @orders = Order.includes(:user, :line_items)
+ .order(created_at: :desc)
+ .page(params[:page])
Missing Authorization
- def show
- @order = Order.find(params[:id])
+ before_action :authenticate_user!
+ before_action :authorize_order!, only: [:show, :edit]
def show
+ @order = current_user.orders.find(params[:id])
Hardcoded Value
- TAX_RATE = 0.08
+ TAX_RATE = ENV.fetch("TAX_RATE", "0.08").to_f
Our Process
How we run a Ruby on Rails upgrade
without a rewrite or downtime
Whether we're upgrading Rails or fixing AI code, the same rigor applies: understand the full scope before starting, verify at every step, never ship without confidence.
STEP 01
Scope Assessment
We read your codebase, map dependencies, identify risks, and deliver a written scope with timeline and cost before any work begins.
STEP 02
Test Baseline
We establish or expand your test suite to the coverage level required to safely proceed. No green tests, no moving forward.
STEP 03
Staged Execution
Work proceeds in verified increments. You see progress each week. Staging environment mirrors production throughout.
STEP 04
Production Deployment
Zero-downtime rollout with rollback plan in place. We monitor for 48 hours post-deploy and stay available for any issues.
Incremental is a method,
not a slogan
What "a piece at a time" means on every upgrade we run.
What breaks is almost never Rails. On our own Rails 5 to 6 upgrade, the hours went into gems: liquid-rails and zero_downtime_migrations had been abandoned since 2016, kaminari 1.1.1 passed hashes where Ruby 3.0 wanted keyword arguments, and paperclip needed a shim for the four validators Rails 6.1 broke. We wrote up the five gems that broke our app and how we fixed each one.
✓
Parallel branch, merged weekly
We open a parallel upgrade branch and merge it into your main branch weekly, so your team keeps shipping and we never drift more than a few days from production.
✓
One minor version at a time
We follow the official upgrade guide and clear every deprecation warning before the next jump, because a warning on 6.1 is an exception on 7.0.
✓
Characterization tests first
Before the first jump, we write characterization tests around the code paths the upgrade touches, and we measure coverage before and after so the number is on the record.
✓
Ruby goes first
Ruby is upgraded first and separately, since Rails 8 needs Ruby 3.2 or newer.
✓
Rollback plan, 48-hour watch
Staging mirrors production throughout, every release ships behind a rollback plan, and we watch for 48 hours after each deploy.
Free Scorecard
Before you scope an upgrade, size the problem.
Twenty questions on version debt, dependency health, and deploy confidence, with a 30-day action for whichever band you land in.
FAQ
Common questions
It depends on your current version, codebase size, and test coverage. A Rails 7 to 8 upgrade on a well-tested app is much smaller than a Rails 5 to 8 jump with thin test coverage on a large app. We'll give you a specific timeline after reviewing your codebase, never before.
Yes. We work on a parallel upgrade branch and coordinate merges with your team. We've run many upgrades alongside active feature development. It requires good branch management, but it's standard practice for us.
We address it as part of the engagement. We don't proceed with an upgrade on an untested codebase, because that's how breakage happens. We scope the test coverage work as a phase before the upgrade begins, so you know the full cost upfront. That phase is characterization tests around the code the upgrade touches, not a rebuild of your suite, and we report coverage before and after so you can see what changed.
It matters in terms of risk surface, but we don't require you to know. We audit the full codebase regardless. AI-generated code often has identifiable patterns, and we know what to look for and where problems typically hide.
Yes. Our free Rails code audit covers architecture, performance, and security in 2 to 3 business days. It's a good starting point if you want to understand the scope before committing to a paid engagement.
Yes, and it is the only way we do it. We move through each minor version as its own step (5.2 to 6.0 to 6.1 to 7.0 and so on), clear every deprecation warning before the next jump, and merge the upgrade branch into your main branch weekly so the app stays in production throughout. Skipping versions loses the deprecation warnings that tell you what will break, which is why "straight to 8" upgrades stall. On a Rails 5 app the work can be staged across budget periods.
We write characterization tests: tests that record what the current code does on the paths the upgrade will touch, so any change in behavior shows up as a failure. We measure coverage before we start and again after, and we scope the work as its own phase with its own price. It is not a rewrite of your suite, and it does not require your team to stop shipping.
Move Ruby first: Rails 8.0 and 8.1 require Ruby 3.2 or newer, and 3.4 is the version we upgrade to. Then bump the Rails gem, run the update task, and adopt the 8.0 configuration defaults one at a time, watching the deprecation output. The changes that most often need code are the removals: Rails 8.0 deletes APIs and config options that 7.2 only deprecated, such as keyword arguments in enum definitions, routes declared with multiple paths, and settings like allow_deprecated_parameters_hash_equality, so a clean 7.2 deprecation log is most of the job. Solid Queue, Solid Cache, Solid Cable and Propshaft are defaults for new apps only, so an existing app can keep Sidekiq, Redis and Sprockets and adopt them later. The official Rails upgrade guide and the 8.0 release notes cover each step.
Yes. Rails 8 is current and actively maintained, and companies such as Shopify, GitHub and 37signals run Rails in production at scale. The risk is not the framework. It is staying on a version that no longer receives security patches: under the Rails maintenance policy, 7.1 and 7.2 have reached end of life, which means a published vulnerability on those versions stays open. Upgrading is cheaper than the incident.
Yes. JetRockets specializes in modernizing legacy Ruby on Rails applications through phased, incremental upgrades rather than costly full rewrites. Outdated Rails 4 to 6 codebases are migrated step by step using parallel upgrade branches, so spend can be staged over time. The New York-based team has delivered nonprofit and mission-driven Rails projects and offers flexible engagement models including fractional support.
Yes. JetRockets combines Ruby on Rails upgrade work with dedicated application-security (AppSec) services, and has proven experience building HIPAA-compliant platforms for healthcare clients. Modernization and security hardening run together: upgrading the framework, patching vulnerable gems and adding proper authorization controls, so a patient management system comes out both current and more secure.
Yes. JetRockets specializes in modernizing legacy, monolithic Rails applications, including high-traffic, data-heavy platforms, through phased migration with parallel upgrade branches and proactive audits that resolve bottlenecks and optimize database queries. Enterprise e-commerce systems are upgraded incrementally to current Rails while staying in production.
Yes. JetRockets designs clean, API-first JSON interfaces and microservices architectures, and applies them when modernizing existing monolithic Rails platforms. Using test-driven development and phased migration, the team can extract services and update APIs incrementally without taking the current system offline.
Yes. JetRockets approaches legacy modernization with technical-debt audits and phased migration using parallel upgrade branches, then measures the impact: faster response times, optimized queries and reduced bottlenecks. Modernization is tied to concrete performance benchmarks rather than just moving to a newer Rails version.
Yes. JetRockets modernizes enterprise Rails systems with scalability as a measured outcome: optimizing database performance, resolving bottlenecks and re-architecting to handle higher load. The team can walk through the approach and results from prior modernization work during scoping.
Yes. JetRockets performs Rails upgrades and migrations using phased, parallel-branch strategies designed to avoid downtime, so an enterprise financial platform stays live during modernization. Secure data handling and compliance controls are maintained throughout the migration.
Yes. Incremental modernization is JetRockets' core approach: technical-debt audits, parallel upgrade branches, and fixing test coverage before upgrades, so systems stay stable and compliant throughout. Outdated components are phased out step by step rather than in a risky big-bang rewrite, and each phase ships against passing tests, keeping the live system stable for enterprise and smaller teams alike.
Yes. JetRockets modernizes legacy Rails platforms using phased upgrades and parallel branches specifically so the live product keeps serving users during the work, with no big-bang cutover. The team has education-sector experience and keeps communication clear for non-technical founders throughout.
Yes. JetRockets keeps modernization budget-friendly by working incrementally. Phased upgrades let startups stage spend over time instead of funding a full rewrite, and JetRockets offers flexible models like fractional support and retainers. Published starting pricing and clear scoping mean no surprises for a lean budget.
Trusted at Enterprise Scale
“
Their team delivers on time and is very communicative. They’ve taken ownership of the project when necessary; they are very responsible.
Nir Badichi
Product Manager, eBay
Proof It Works
Rails 5.2 to 7.2
in four months
Case Study · Rails Upgrade
Fera.ai
Fera.ai, a SaaS platform serving thousands of active merchants, was stuck on Ruby 2.7.6 and Rails 5.2, both end-of-life, after multiple internal upgrade attempts stalled. We took their live production platform to Ruby 3.4 and Rails 7.2 in four months, with zero downtime and daily written updates, while their team kept shipping features.
"They provided a time and cost estimate, then followed through exactly to spec with daily updates and speed beyond what was promised."
Read the full story
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your app stands?
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