A curated repository of system design problems commonly asked in SDE interviews, featuring both High-Level Design (HLD) and Low-Level Design (LLD) documents, with architecture diagrams and detailed explanations.
✅ = Available | ⏳ = Coming Soon
| # | System Design Problem | Resources |
|---|---|---|
| 1 | ✅ Ticket Booking System (like BookMyShow) | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 2 | ✅ URL Shortener | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 3 | ✅ Rate Limiter | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 4 | ⏳Ride Sharing App | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 5 | ⏳Social Media Application (like Instagram) | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 6 | ⏳Parking Lot System | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 7 | ⏳Elevator System | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 8 | ⏳Cab Booking System (like Uber/Ola) | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 9 | ⏳Hotel Room Booking System (like OYO) | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 10 | ⏳Library Management System | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 11 | ⏳Online Food Delivery System (like Zomato/Swiggy) | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 12 | ⏳Splitwise (Expense Splitter) System | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 13 | ⏳Stock Trading System | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 14 | ⏳ATM System | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 15 | ⏳Notification System (email, SMS, push notifications) | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 16 | ⏳Cache (LRU, LFU) | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 17 | ⏳Logger System with Different Log Levels | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 18 | ⏳File Storage System (like Google Drive) | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 19 | ⏳Task Scheduler | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 20 | ⏳Vending Machine | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 21 | ⏳In-Memory Key-Value Store (like Redis) | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 22 | ⏳API Gateway | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 23 | ⏳Metrics Collector and Aggregator | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 24 | ⏳Notification Rate Controller (like WhatsApp message flood control) | HLD 📘 | LLD 📙 | Diagram 🖼️ |
| 25 | ⏳Auth System (JWT, session or OAuth) | HLD 📘 | LLD 📙 | Diagram 🖼️ |
Love system design? Found something to improve or want to add a new problem? We welcome pull requests and feedback!
- Aditya Pande – Initial setup & core content