PEDALS-guided design walkthroughs with linked calculators and databases.
Pick a guided design challenge or start with a blank canvas.
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Free-form PEDALS walkthrough without a preset prompt
Design a Chat System
Design a real-time messaging platform supporting 1:1 chats, group chats, online presence, and message delivery guarantees.
Design a Notification System
Design a scalable notification platform that delivers push, SMS, and email notifications with user preferences and rate limiting.
Design a URL Shortener
Design a URL shortening service like bit.ly that generates short aliases for long URLs and redirects users efficiently.
Design a Web Crawler
Design a distributed web crawler that can index billions of pages, respect politeness policies, and handle diverse content types.
Design Pastebin
Design a text-sharing service like Pastebin that lets users create, share, and retrieve short text snippets via unique URLs.
Design Twitter Feed
Design the home timeline feed for a Twitter-like social platform supporting millions of users, fan-out, and real-time delivery.
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