Architecture Overview When creating an e-commerce platform, I followed the principles of modular architecture and separation of concerns. Core Modules 1. Catalog — product catalog management 2. Cart — shopping cart 3. Checkout — order checkout process 4. User — user management and authentication 5. Orders — order history 6. Payments — payment system integration Data Structure Product Schema typescript interface Product { id: string slug: string name: string description: string price: number comparePrice?: number images: string category: Category variants: ProductVariant stock: number featured: boolean } interface ProductVariant { id: string name: string options: Record<string, string> // { "Size": "M", "Color": "Blue" } price: number stock: number sku: string } Order Schema typescript interface Order { id: string orderNumber: string userId: string items: OrderItem subtotal: number tax: number shipping: number total: number status: OrderStatus shippingAddress: Address billingAddress: Address paymentMethod: PaymentMethod createdAt: string } State Management Using Zustand for state management: typescript // stores/cart-store.ts import { create } from 'zustand' import { persist } from 'zustand/middleware' interface CartState { items: CartItem addItem: product: Product, quantity: number => void removeItem: productId: string => void updateQuantity: productId: string, quantity: number => void clearCart: => void total: => number } export const useCartStore = create<CartState> persist set, get => { items: , addItem: product, quantity => { setstate => { items: ...state.items, { product, quantity } } }, removeItem: productId => { setstate => { items: state.items.filteritem => item.product.id !== productId } }, updateQuantity: productId, quantity => { setstate => { items: state.items.mapitem => item.product.id === productId ? { ...item, quantity } : item } }, clearCart: => set{ items: }, total: => { return get.items.reduce sum, item => sum + item.product.price item.quantity, 0 } }, { name: 'cart-storage' } Performance Optimization Data Caching typescript // Static generation for product pages export async function generateStaticParams { const products = await getProducts return products.mapproduct => { slug: product.slug } } // Revalidation every 60 seconds export const revalidate = 60 Optimistic Updates typescript const addToCart = async product: Product => { // Optimistically update UI useCartStore.getState.addItemproduct, 1 try { // Send request to server await fetch'/api/cart', { method: 'POST', body: JSON.stringify{ productId: product.id, quantity: 1 } } } catch error { // Rollback changes on error useCartStore.getState.removeItemproduct.id toast.error'Failed to add to cart' } } Results The architecture provides: - ⚡ Fast page loading LCP < 2s - 📦 Modularity and easy maintenance - 🔄 Optimistic UI updates - 💾 Cart state persistence - 🛡️ Type-safe code at all levels