| 1. Design a URL Shortener | | Easy+ 2 |
| 2. Design a Prompt Playground | | Normal 3 |
| 3. Design Search Autocomplete | | Normal 3 |
| 4. Design a Chess Matchmaking System | | Normal+ 4 |
| 5. Design a Distributed Rate Limiter | | Normal+ 4 |
| 6. Design a Notification Service | +1 | Normal+ 4 |
| 7. Design a RAG Assistant | | Normal+ 4 |
| 8. Design a Top K Trending Service | +1 | Normal+ 4 |
| 9. Design a Web Crawler | | Normal+ 4 |
| 10. Design Netflix | +1 | Normal+ 4 |
| 11. Design Twitter's Home Timeline | | Normal+ 4 |
| 12. Design a Batched LLM Inference API | | Hard 5 |
| 13. Design a CI/CD System | | Hard 5 |
| 14. Design a Content Moderation System | | Hard 5 |
| 15. Design a GPU Scheduler for Video Generation | | Hard 5 |
| 16. Design a Payment System | | Hard 5 |
| 17. Design a Ticket Booking System | +1 | Hard 5 |
| 18. Design an LLM Gateway | +1 | Hard 5 |
| 19. Design Dropbox | | Hard 5 |
| 20. Design Model Weight Distribution to 1,000 GPUs | | Hard 5 |
| 21. Design Permission-Aware Enterprise Search | | Hard 5 |
| 22. Design Slack | | Hard 5 |
| 23. Design Uber | | Hard 5 |
| 24. Design WhatsApp | | Hard 5 |
| 25. Design a Distributed Key-Value Store | +1 | Harder 6 |
| 26. Design an AI Coding Agent | +1 | Harder 6 |
| 27. Design ChatGPT's Inference Service | +1 | Harder 6 |
| 28. Design Google Docs | | Harder 6 |
| 29. Design Search Over a Billion Documents | | Harder 6 |
| 30. Design TikTok's For You Feed | | Harder 6 |