Deploy your Flask app to Fly.io
Step-by-step deployment help for Flask apps on Fly.io. We fix Flask-specific deployment issues, configure Fly.io, and get your app live. From $19.
Flask issues we fix before deploying
Common Flask problems that affect Fly.io deployments.
Debug mode in production
Flask's built-in debugger left enabled in production, exposing an interactive console that allows remote code execution on the server.
Hardcoded secret key
SECRET_KEY set to a default or short string like 'secret' instead of a cryptographically random value loaded from environment variables.
No CSRF protection
Forms and state-changing endpoints without Flask-WTF CSRF tokens, enabling cross-site request forgery attacks.
Running with flask run in production
Using Flask's development server in production instead of gunicorn or uWSGI, which is single-threaded and not designed for real traffic.
Fly.io deployment issues we check for
Common Fly.io problems that break Flask 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 Flask 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 Flask app to Fly.io?
We handle Flask deployments to Fly.io end to end. Start with our code audit ($19) to identify deployment blockers specific to your Flask project, then we configure Fly.io, fix issues, and get your app live in production.
What Flask issues affect Fly.io deployments?
Flask projects commonly have debug mode in production and hardcoded secret key. 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 Flask project to Fly.io?
Yes. We specialize in deploying Flask applications to Fly.io. We audit your codebase for Flask-specific issues, configure Fly.io correctly, and handle the full deployment so your app runs reliably in production.
What does Flask deployment to Fly.io cost?
Our code audit ($19) identifies all Fly.io deployment blockers in your Flask 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 Flask elsewhere
Need help deploying Flask to Fly.io?
Tell us about your project. We'll respond within 24 hours with a clear plan and fixed quote.