System design interview problems
Each one written out from requirements to trade-offs.
Start here
Design a URL Shortener
Best first problem. Covers ID generation, caching and read-heavy design in about 45 minutes.
easyThen
Design a Rate Limiter
Every API needs one. Tests distributed counters, Redis atomicity, and failure modes.
mediumThen
Design WhatsApp
The classic hard problem. Touches real-time connections, fan-out, and message ordering.
hardProblemTopicLevelUpdated
Design a Distributed CacheCachingmediumAug 14Design a News FeedDatabaseshardJun 12Design a Rate LimiterDatabasesmediumSep 2Design a URL ShortenerDatabaseseasyJul 3Design LeetCodeDistributed SystemsmediumSep 19Design a Job SchedulerMessaging & QueuesmediumSep 10Design TicketmasterReal-time SystemshardJul 2Design WhatsAppReal-time SystemshardJul 2Design DropboxStoragehardJul 29 of 9 shown