We get asked this a lot: "Why Rails and Flutter?" Usually by founders who've been told Rails is dead, or that Flutter is just for prototypes, or that they should be using Next.js and React Native instead.
Here's the short answer: Rails and Flutter let us ship production apps faster than any other stack we've used in 15+ years of building software. Here's the long answer.
What Is Ruby on Rails?
Ruby on Rails is a backend web framework that's been around since 2004. It powers some of the biggest products you use daily — Shopify, GitHub, Basecamp, Airbnb (early versions), and Hulu. It's designed for developer productivity: you can build a working API or web app in a fraction of the time it takes in most other frameworks.
Rails is opinionated. It makes decisions for you — how to structure your code, how to talk to the database, how to handle authentication. That sounds restrictive, but for startups it's a superpower. You spend time building your product instead of debating architecture.
What Is Flutter?
Flutter is Google's cross-platform mobile framework. One codebase produces native apps for iOS, Android, web, and desktop. It launched in 2018 and has grown rapidly — used by companies like BMW, Google Pay, Alibaba, and Toyota.
Flutter compiles to native ARM code, so it's fast. It uses its own rendering engine (Skia/Impeller), so your app looks and feels identical on both platforms. And Dart (Flutter's language) is straightforward — any developer who knows Java, JavaScript, or Swift picks it up quickly.
Why We Pair Them
Rails handles the backend: API endpoints, database, authentication, business logic, admin dashboards, background jobs, email delivery. Flutter handles the frontend: the mobile app your users actually touch.
This pairing works because:
- Speed to market. Rails scaffolds APIs incredibly fast. Flutter builds both iOS and Android from one codebase. Combined, we can ship an MVP in 6-10 weeks that would take 4-6 months with separate native apps and a custom backend.
- One codebase per layer. One backend (Rails). One frontend (Flutter). Not two native mobile codebases, not a backend-for-frontend plus a separate API. Fewer codebases means fewer bugs, lower maintenance costs, and easier onboarding for new developers.
- Battle-tested at scale. Rails handles millions of requests per day at companies like Shopify and GitHub. Flutter runs production apps at Google and BMW. These aren't experimental technologies — they're proven.
- Great developer experience. Happy developers ship better code faster. Both Rails and Flutter are designed for developer productivity, with strong tooling, active communities, and excellent documentation.
When to Use Rails
Rails is the right backend choice when:
- You're building an API-backed mobile app. Rails + a REST or GraphQL API is a natural fit for Flutter frontends.
- You need to move fast. Rails conventions mean less time on boilerplate and more time on features.
- You have standard web app needs: user authentication, database CRUD, email, background jobs, file uploads, admin panels. Rails has mature, well-tested solutions for all of these.
- Your team is small. A single Rails developer can build what would take 2-3 developers in more verbose frameworks.
Rails is not the best choice for real-time streaming applications, extremely high-throughput event processing, or systems where microsecond latency matters. For those, you'd look at Elixir, Go, or Rust. But for 90% of startup backends, Rails is more than fast enough.
When to Use Flutter
Flutter is the right frontend choice when:
- You need iOS and Android. One codebase, one team, one deployment pipeline. The cost savings vs. building two native apps are significant — typically 30-40%.
- Design matters. Flutter gives you pixel-perfect control over every element. Custom animations, unique UI patterns, brand-specific design systems — Flutter handles them better than most cross-platform alternatives.
- Performance matters. Flutter compiles to native code. It's not running in a JavaScript bridge like React Native. For apps with complex animations, maps, camera integration, or real-time features, the performance difference is noticeable.
- You want to add AI features. Flutter works well with REST APIs, which is how you connect to AI services like OpenAI, AWS Rekognition, and Google Cloud ML. The ecosystem for AI integration is growing fast.
Flutter is not the best choice if you're building a content-heavy website (use Astro or Next.js), a simple CRUD admin tool (use Rails views or a React admin panel), or if your app is deeply tied to platform-specific APIs that don't have Flutter plugins yet.
Rails + Flutter vs. the Alternatives
| Stack | Strengths | Tradeoffs |
|---|---|---|
| Rails + Flutter | Fast to ship, one codebase per layer, battle-tested | Smaller talent pool than JS-based stacks |
| Node.js + React Native | Huge JS ecosystem, shared language front-to-back | React Native bridge = slower, more native module headaches |
| Django + Flutter | Python ecosystem, good for ML-heavy backends | Django is slower to develop in than Rails for typical web apps |
| Firebase + Flutter | No backend to manage, fast prototyping | Vendor lock-in, costs spike at scale, limited business logic |
| Next.js + React Native | Vercel ecosystem, SSR, great for web-first | Two React codebases (web + mobile) = more complexity than it seems |
Real Examples from Our Work
A few examples of what Rails + Flutter looks like in production:
- Health tech app: Rails API handling patient data with HIPAA compliance, Flutter frontend for iOS and Android. Shipped MVP in 8 weeks.
- SaaS platform: Rails backend with multi-tenant architecture, Flutter mobile app for field workers. API handles 50K+ requests/day.
- Consumer marketplace: Rails powers the matching algorithm and payment processing, Flutter delivers the user experience. Single developer maintained both codebases post-launch.
In every case, the Rails + Flutter stack let us ship faster, with fewer developers, and with a cleaner architecture than the alternatives we evaluated.
"But Isn't Rails Dead?"
No. This comes up every year, and every year it's wrong. Rails 8 shipped in late 2024 with significant performance improvements and built-in deployment tooling. Shopify — a $100B+ company — runs entirely on Rails and continues to invest heavily in it. GitHub runs on Rails. Basecamp, Hey, Cookpad, Kickstarter — all Rails.
Rails isn't trendy. It's mature. For startups, "mature" means fewer surprises, better documentation, and a framework that won't break your app with a major version update.
"But Isn't Flutter Just for Prototypes?"
Also no. Google Pay, BMW, Alibaba, eBay Motors, Nubank (the world's largest digital bank), and Toyota all run Flutter in production. Flutter's rendering engine was completely rewritten (Impeller) for production performance. It's not a prototype tool — it's a production framework backed by one of the largest tech companies in the world.
If you're evaluating stacks for your next project, we're happy to walk through the tradeoffs for your specific use case. Start a conversation with us.
