Guided practice

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

• 

  5. Design a Chat System

  Send durable messages, reconnect devices and explain ordering and delivery receipts.

  ClassicMedium

  DatabasesSecurityPrivacy

  +11

  Distributed systemsAWSChatDynamoDBEnd to end encryptionMessagingMulti regionOffline firstOrderingRedis Pub/SubWebSockets

  Worked design

  Practice
• 

  59. Design a Fitness Tracking App like Strava

  Record runs and rides on the phone without signal, upload each once, show them to friends and rank athletes by week, month and year.

  ClassicMedium

  CachingDatabasesAWS

  +6

  DynamoDBFitnessGPSLeaderboardsOffline firstRedis

  Worked design

  Practice

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