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Classic designs 4

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48. Design a Ticket Booking System like Ticketmaster
Hold seats with one conditional write, pay by authorize and capture, and put ten million fans in a fair waiting room without selling a seat twice.
ClassicMedium
Search Concurrency Aurora
+5
AWS Booking OpenSearch Ticketing Waiting room
Worked design
Practice
49. Design an Online Auction like eBay
Take bids on 10 million live auctions with one consistent highest bid, lose none, push the price to every watcher and end each auction fairly.
ClassicMedium
Streaming Concurrency Distributed systems
+7
Auctions Aurora AWS Contention Kafka Real time Server sent events
Worked design
Practice
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
Caching Databases Concurrency
+6
Aurora AWS Flash sale Inventory Redis Waiting 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
Concurrency AWS Contention
+3
Flash sale Locking Sagas
Worked design
Practice

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