Loading system design...
Design a large-scale e-commerce platform like Flipkart or Amazon. The system supports product listing by sellers, product search with faceted filters, shopping cart, checkout with multiple payment methods, inventory management that prevents overselling, order tracking with logistics integration, personalised recommendations, and flash sales that handle 100× traffic spikes.
| Metric | Value |
|---|---|
| Registered users | 500 million |
| Daily active users (DAU) | 50 million |
| Products (SKUs) | 200 million |
| Product searches per day | 2 billion |
| Orders per day | 10 million |
| Peak orders per minute (flash sale) | 200,000 |
| Cart operations per day | 500 million |
| Average order value | ₹1,200 (~$15) |
| Sellers | 1 million |
| Warehouses | 100+ across the country |
| Product images stored | 5 billion |
Product catalogue: sellers list products with title, description, images, price, variants (size/colour), category, and stock quantity; support millions of SKUs across categories
Product search: full-text search with filters (category, brand, price range, rating, delivery speed), sorting (relevance, price, popularity, newest), and faceted navigation
Product detail page: display product info, images, pricing, seller details, reviews/ratings, delivery estimate, stock availability, and 'frequently bought together' recommendations
Shopping cart: add/remove/update items; persist cart across sessions and devices; show real-time price, availability, and delivery estimate per item
Checkout and payment: address selection, shipping method, coupon/promo code, payment (credit card, UPI, wallet, COD, EMI); atomic order placement with inventory deduction
Inventory management: track stock per SKU per warehouse; prevent overselling; real-time stock decrement on order; restock alerts for sellers
Order management: order status tracking (placed → confirmed → packed → shipped → out for delivery → delivered); real-time tracking with delivery partner integration
Reviews and ratings: users rate products (1–5 stars) and write text reviews with images; aggregate ratings; helpful/report review; verified purchase badge
Recommendations: personalised 'recommended for you' on homepage, 'frequently bought together' on product page, 'similar products', and 'recently viewed'
Flash sales: time-limited deals with limited inventory (e.g., Big Billion Days); handle extreme traffic spikes (100× normal); fair queuing; countdown timers
Non-functional requirements define the system qualities critical to your users. Frame them as 'The system should be able to...' statements. These will guide your deep dives later.
Think about CAP theorem trade-offs, scalability limits, latency targets, durability guarantees, security requirements, fault tolerance, and compliance needs.
Frame NFRs for this specific system. 'Low latency search under 100ms' is far more valuable than just 'low latency'.
Add concrete numbers: 'P99 response time < 500ms', '99.9% availability', '10M DAU'. This drives architectural decisions.
Choose the 3-5 most critical NFRs. Every system should be 'scalable', but what makes THIS system's scaling uniquely challenging?