Deploy your Ruby on Rails app to Fly.io
Step-by-step deployment help for Ruby on Rails apps on Fly.io. We fix Ruby on Rails-specific deployment issues, configure Fly.io, and get your app live. From $19.
Ruby on Rails issues we fix before deploying
Common Ruby on Rails problems that affect Fly.io deployments.
Mass assignment vulnerabilities
AI-generated Rails controllers that use permit! or don't properly whitelist params, allowing attackers to modify any database column including admin flags and passwords.
Missing authorization checks
Controllers that authenticate users but don't check authorization — a logged-in user can access or modify any other user's data by changing the ID in the URL.
N+1 query problems
ActiveRecord code that loads associated records in loops without includes, eager_load, or preload — causing hundreds of database queries on pages with lists.
Unsafe use of raw SQL
AI tools sometimes generate raw SQL with string interpolation instead of using ActiveRecord's parameterized query methods, enabling SQL injection attacks.
Fly.io deployment issues we check for
Common Fly.io problems that break Ruby on Rails apps in production.
Dockerfile missing or misconfigured
Fly.io requires a Dockerfile for deployment. AI tools that scaffold without one force flyctl to auto-generate a suboptimal Dockerfile that misses build steps.
Volume only available in a single region
Fly volumes are pinned to one region. Multi-region deployments try to access a volume that doesn't exist in other regions, causing crashes.
Machine restarts losing in-memory state
AI-generated apps store session data or caches in memory. Fly machines can restart or migrate, wiping all in-memory state without warning.
Internal DNS resolution failing between services
Services within a Fly organization communicate via <app>.internal hostnames, but AI-generated code hardcodes localhost or public URLs.
Start with a self-serve audit
Get a professional review of your Ruby on Rails project before deploying to Fly.io.
External Security Scan
Black-box review of your public-facing app. No code access needed.
- OWASP Top 10 vulnerability check
- SSL/TLS configuration analysis
- Security header assessment
- Expert review within 24h
Code Audit
In-depth review of your source code for security, quality, and best practices.
- Security vulnerability analysis
- Code quality review
- Dependency audit
- Architecture review
- Expert + AI code analysis
Complete Bundle
Both scans in one package with cross-referenced findings.
- Everything in both products
- Cross-referenced findings
- Unified action plan
100% credited toward any paid service. Start with an audit, then let us fix what we find.
How it works
Tell us about your app
Share your project details and what you need help with.
Expert + AI audit
A human expert assisted by AI reviews your code within 24 hours.
Launch with confidence
We fix what needs fixing and stick around to help.
Frequently asked questions
How do I deploy a Ruby on Rails app to Fly.io?
We handle Ruby on Rails deployments to Fly.io end to end. Start with our code audit ($19) to identify deployment blockers specific to your Ruby on Rails project, then we configure Fly.io, fix issues, and get your app live in production.
What Ruby on Rails issues affect Fly.io deployments?
Ruby on Rails projects commonly have mass assignment vulnerabilities and missing authorization checks. On Fly.io, these combine with dockerfile missing or misconfigured and volume only available in a single region to cause deployment failures.
Can SpringCode deploy my Ruby on Rails project to Fly.io?
Yes. We specialize in deploying Ruby on Rails applications to Fly.io. We audit your codebase for Ruby on Rails-specific issues, configure Fly.io correctly, and handle the full deployment so your app runs reliably in production.
What does Ruby on Rails deployment to Fly.io cost?
Our code audit ($19) identifies all Fly.io deployment blockers in your Ruby on Rails project. Full deployment assistance is scoped with a fixed quote after the audit — no hourly billing or surprise charges.
Related resources
Other techs on Fly.io
Deploy Ruby on Rails elsewhere
Need help deploying Ruby on Rails to Fly.io?
Tell us about your project. We'll respond within 24 hours with a clear plan and fixed quote.