Project 3 — SaaS-Style Frontend (Auth, Billing & Protected Flows)

🧭 Introduction

Most modern React jobs involve SaaS products:

  • Subscription-based access
  • Role-based features
  • Protected routes
  • Account settings
  • Usage limits

This project teaches you how to build a SaaS-style frontend architecture, exactly like real companies do.

⚠️ This project focuses on architecture, flow, and scalability, not just UI.

After this project, you’ll think like a SaaS frontend engineer.


🎯 Project Goals

By completing this project, you will learn how to:

  • Design SaaS-style frontend architecture
  • Implement authentication-based flows
  • Handle protected routes & plans
  • Build subscription-aware UI
  • Handle onboarding & account lifecycle
  • Manage feature access cleanly
  • Structure large React applications

🧠 What We Are Building

SaaS Frontend Application

Core features:

  • Login / Register
  • Onboarding flow
  • Subscription plans (Free / Pro / Enterprise)
  • Protected routes
  • Feature gating
  • Account & billing screens
  • Dashboard with restricted features

🧩 SaaS User Lifecycle (Important Concept)

Visitor
 → Register
 → Login
 → Onboarding
 → Free Plan
 → Upgrade
 → Active Subscriber

Your UI must react to each stage.


🏗️ High-Level Architecture

src/
│
├── auth/                 → Login, register, auth context
├── billing/              → Plans, pricing, subscription logic
├── onboarding/           → First-time user flow
├── dashboard/            → Core SaaS features
├── routes/               → Route protection & guards
├── components/           → Shared UI components
├── hooks/                → Custom hooks
├── api/                  → API layer
├── context/              → Global contexts
├── types/                → TypeScript types

This mirrors real SaaS codebases.


🔐 Authentication Flow (Recap Applied)

  • JWT-based authentication
  • Token persistence
  • Protected routes
  • Role-based access
<ProtectedRoute>
  <Dashboard />
</ProtectedRoute>


🧠 Onboarding Flow (SaaS-Specific)

New users should not see the dashboard immediately.

Instead:

  • Complete profile
  • Choose plan
  • Accept terms
if (!user.isOnboarded) {
  return <Navigate to="/onboarding" />;
}

This is very common in real SaaS apps.


💳 Subscription Plans & Feature Gating

Plans

  • Free
  • Pro
  • Enterprise
type Plan = "free" | "pro" | "enterprise";


Feature Access Logic

const featureAccess = {
  free: ["dashboard"],
  pro: ["dashboard", "analytics"],
  enterprise: ["dashboard", "analytics", "team"]
};


Feature Guard Component

function FeatureGuard({ feature, children }) {
  const { plan } = useAuth();

  if (!featureAccess[plan]?.includes(feature)) {
    return <UpgradePrompt />;
  }

  return children;
}


🧠 Using Feature Guard

<FeatureGuard feature="analytics">
  <AnalyticsDashboard />
</FeatureGuard>

✔ Clean
✔ Declarative
✔ Scalable


📊 Dashboard Design

Dashboard includes:

  • Overview
  • Usage stats
  • Feature-specific sections

Each section checks:

  • Auth
  • Plan
  • Role

🧠 Billing Page (Frontend Perspective)

The frontend:

  • Displays current plan
  • Shows upgrade options
  • Sends intent to backend
<button onClick={() => upgradePlan("pro")}>
  Upgrade to Pro
</button>

Backend handles actual payments.


🛡️ Route-Level Protection (Combined Guards)

<Route
  path="/analytics"
  element={
    <ProtectedRoute>
      <FeatureGuard feature="analytics">
        <Analytics />
      </FeatureGuard>
    </ProtectedRoute>
  }
/>

This layered protection is enterprise-grade.


🧠 Error Handling Strategy

  • Error Boundaries at layout level
  • Global error banner for API issues
  • Auth failures redirect to login

No crashes. No blank screens.


🧪 Testing Strategy (Applied)

Tests cover:

  • Auth redirects
  • Feature gating behavior
  • Plan upgrades
  • Unauthorized access

Example:

expect(screen.getByText("Upgrade Required"))
  .toBeInTheDocument();


🔷 TypeScript Usage

  • Typed plans & roles
  • Typed feature flags
  • Typed API responses

This prevents:
❌ Invalid plan logic
❌ Broken feature access


⚡ Performance Considerations

  • Lazy-loaded routes
  • Code splitting by feature
  • Memoized heavy components

SaaS apps must stay fast.


🎯 Real-World Skills You Gain

After this project, you can say:

✅ I can build SaaS frontends
✅ I understand subscription logic
✅ I can gate features safely
✅ I can design scalable React apps
✅ I think like a product engineer


❓ FAQs — Project 3

🔹 Is this close to real SaaS apps?

Yes — very close.


🔹 Does frontend handle payments?

No — backend does. Frontend handles flow.


🔹 Is this project resume-worthy?

Absolutely.


🔹 Can I deploy this?

Yes — with mock billing APIs.


🧠 Quick Recap

✔ SaaS lifecycle handling
✔ Auth + onboarding
✔ Subscription plans
✔ Feature gating
✔ Scalable architecture


🎉 Conclusion

This project transforms your mindset from:

“I can build pages”

to:

“I can build SaaS products.”

That’s a huge career milestone 🚀⚛️


👉 Next Project

Project 4 — SaaS Dashboard with API (Real-Time Data & Analytics)

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