Guided practice

Company tags are community-reported. Counts on cards show how many people reported that design.

• 

  88. Design a Reviews and Ratings System

  Dish reviews only from customers who ordered them, votes counted from a change stream, reviews ranked by the Wilson bound, payouts made exactly once.

  ClassicMedium

  DatabasesStreamingDistributed systems

  +7

  AWSDynamoDBKafkaRankingRatingsReviewsSocial

  Worked design

  Practice
• 

  92. Design Online Chess

  Real-time rated chess with server-validated moves, lag-compensated clocks, pairing by rating and a million watchers on one game.

  ClassicMedium

  DatabasesAWSDynamoDB

  +4

  GamingMatchmakingRatingsWebSockets

  Worked design

  Practice

Self-paced by default. Your answers and canvas stay private. AI feedback runs only when you ask for it.