Guided practice

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

• 

  62. Design a Flash Sale System

  Sell 10,000 units to a million people at noon with a lottery waiting room, a Redis gate before an Aurora ledger and holds that expire.

  ClassicMedium

  CachingDatabasesConcurrency

  +6

  AuroraAWSFlash saleInventoryRedisWaiting room

  Worked design

  Practice
• 

  64. Design for Contention: Thousands Racing for the Same Item

  Design for contention through a limited sneaker drop: row locks, conditional writes, expiring holds, fencing tokens, sagas and one writer per item.

  ClassicMedium

  ConcurrencyAWSContention

  +3

  Flash saleLockingSagas

  Worked design

  Practice

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