When will you use this?

Use this lesson to build something you can show in interviews and on your resume.

• Portfolio projects prove you can finish — recruiters click your demo link.
• Build one dashboard or shop end-to-end; that beats ten half-finished tutorials.

Real-world: Flipkart-like seller dashboard

Real product: Flipkart-like seller dashboard (E-commerce). sellers and ops teams rely on order list and inventory counts every day. On this product, developers use E-Commerce Storefront Project to apply E-Commerce Storefront Project when building interactive screens on Flipkart-like seller dashboard. Without it, the team would ship slower, introduce more bugs, or hit performance walls as user count grows. The example below is simplified on purpose — the same pattern appears in production with error handling, loading states, and tests added around it.

Production-style code

const useCart = create(set => ({
  items: [],
  add: product => set(s => ({
    items: [...s.items, { ...product, qty: 1 }]
  })),
  total: () => get().items.reduce((sum, i) => sum + i.price * i.qty, 0)
}));

What happens in production: In Flipkart-like seller dashboard, getting E-Commerce Storefront Project right means sellers and ops teams see a fast, correct order list and inventory counts. That is the difference between a demo and software people trust with real money, health data, or grades.

Lesson example (start here)

Copy this smaller example first. Once it works, compare it with the real-world code above.

const useCart = create(set => ({
  items: [],
  add: product => set(s => ({
    items: [...s.items, { ...product, qty: 1 }]
  })),
  total: () => get().items.reduce((sum, i) => sum + i.price * i.qty, 0)
}));

Line-by-line walkthrough

How it works (big picture)

• Zustand or Context holds cart across pages.
• Product list from useQuery.
• Checkout form validates shipping fields.

Do this on your computer

1. Product list + detail pages with Router.
2. Add cart store and badge count.
3. Checkout form with order summary.
4. Read the real-world section and name which part of the app uses this topic.
5. Run the example locally and confirm the same behavior in the browser.
6. Change one value in the example (text, initial state, or URL) and predict what will happen before you save.

Experiments — try changing this

• Change text or labels in the example and save — watch the browser update.
• Break the code on purpose (remove a bracket), read the error message, then fix it.

Remember

Catalog + cart + checkout flow. Global cart state. API for products, mock payments OK for learning.

Common questions