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Concept guides/Consistency and money/Making a write safe to retry

System designConsistency and money

Making a write safe to retry

Medium7 min read

Questions it teaches

Fix the charge counter for a retrying clientEasy10 min Fix the payout consumer that skips repeat deliveriesEasy12 min Fix the duplicate charge guard in an SQS consumerEasy10 min Fix the stock count fold for inventory eventsEasy10 min Spec a bank and ledger CSV reconciliation scriptEasy20 min Spec a Bash deploy script that can roll backMedium25 min Review PR #529: refund a typed amount in any currencyMedium30 min Spec a refund endpoint that cannot over-refundHard30 min

Related

Consistency and money Messaging and streams Data modeling and storage Scale and caching Real-time systems Backend internals Reliability and failover

Builds on: Messaging and streams

Designing team chat3 min Real-time personalization4 min

Builds on: Data modeling and storage

Designing a parking lot4 min Designing a pastebin3 min

Related: Scale and caching

Connection pool proxy3 min Connection pooling proxy (gateway)3 min

Related: Real-time systems

Short polling for presence4 min URL routing3 min

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