Practice. Design. Excel.

Design a URL shortening service like TinyURL or bit.ly.

Design a text storage service like Pastebin where users can store and share text segments.

Design a Hit Counter that counts the number of hits in the past 5 minutes.

Design a real-time leaderboard for a massive online game.

Design a distributed Key-Value store like Redis or DynamoDB.

Design a system to distribute requests uniformly across a dynamic set of servers.

Design a scalable notification system to send millions of notifications (Email, SMS, Push).

Design a scalable social media platform like Twitter (now X).

Design a real-time messaging application like WhatsApp.

Design the backend for a ride-sharing service like Uber/Lyft.

Design a photo-sharing news feed like Instagram.