System Design Cases
Design a URL shortener, a chat app, a feed — the interview round, end to end.
System Design Cases progress0 / 20
- Design a URL ShortenerOne tiny key, a hundred million long links behind it.6m
- Design a Rate LimiterThe algorithm is easy; where the counter lives is the interview.6m
- Design a Chat AppFinding the socket is harder than sending the message.7m
- Design a News FeedPay at write time, at read time, or a little of both.7m
- Design a Notification SystemOne event, three channels, and never the same message twice.6m
- Design Search AutocompleteNot a search — a walk down a path somebody built last night.6m
- Design a File Storage ServiceUpload the paragraph that changed, not the ten gigabytes.7m
- Design Video StreamingTranscode once, cut into segments, and let the edge carry it.7m
- Design Ride MatchingThe write rate is the problem; the search is one cell lookup.7m
- Design a Payment LedgerNothing is ever edited — a correction is one more line.7m
- Design a Job SchedulerThe worker died mid-job. The ticket goes back on the rail.7m
- Design Geo Proximity SearchTwo numbers, one index: fold a map down into a sorted string.7m
- Design E-commerce InventoryOne unit left, two carts, and only one of them may hear yes.7m
- Design Ad Click AggregationThe same click arrives twice, late, and out of order.7m
- Design a Distributed CacheA ring of machines where losing one moves only its own arc.7m
- Design a Key-Value StoreThree copies, two acks, two reads — the sets have to overlap.7m
- Design a Web CrawlerA billion pages, one polite knock per host, nothing fetched twice.7m
- Design a LeaderboardKeep it sorted on the way in, and the top hundred is free.6m
- Design Hotel BookingFour nights or none — a partial stay is not a booking.7m
- Design a Collaborative EditorBoth typing in one paragraph, both landing on the same text.7m
Quiz yourself: 3 questions from this module
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