Questions
Status
Seat booking for a community theaterEasyDesignDesignEasy25 minShared expenses for a group of friendsEasyDesignDesignEasy25 minCheckout for an online course storeEasyDesignDesignEasy25 minLoyalty points for a coffee chainEasyDesignDesignEasy30 minTransfers between a member's own accountsEasyDesignDesignEasy25 minRead replica staleness routingMediumDesignDesignMedium40 minQuery batching layerMediumDesignMeta styleDesignMeta styleMedium35 minHot stories rankingMediumDesignDesignMedium40 minIdempotency key storage and concurrencyMediumDesignStripe styleDesignStripe styleMedium40 minDouble-entry accounting atomicity and floorsMediumDesignStripe styleDesignStripe styleMedium40 minDesign a refund serviceMediumDesignStripe styleDesignStripe styleMedium40 minTrial balance and period closeMediumDesignIntuit styleDesignIntuit styleMedium40 minStored-value card platformMediumDesignStarbucks styleDesignStarbucks styleMedium40 minSubscription refunds and creditsMediumDesignStripe styleDesignStripe styleMedium40 minRecurring billing engineMediumDesignStripe styleDesignStripe styleMedium40 minBank feed reconciliationMediumDesignStripe styleDesignStripe styleMedium40 minMulti-master preferences conflict resolutionMediumDesignAmazon styleDesignAmazon styleMedium35 minMulti-region read scalingMediumDesignDesignMedium40 minService discovery and config distributionMediumDesignNetflix styleDesignNetflix styleMedium40 minGlobal username uniqueness at signupMediumDesignDesignMedium35 minDistributed cron single-execution guaranteeMediumDesignGoogle styleDesignGoogle styleMedium35 minResumable chunked uploadMediumDesignGoogle styleDesignGoogle styleMedium40 minS3-compatible object storageMediumDesignAmazon styleDesignAmazon styleMedium40 minCache invalidation at scaleMediumDesignMeta styleDesignMeta styleMedium45 minEdge feature-flag evaluationMediumDesignDesignMedium35 minRequest coalescing and batchingMediumDesignDesignMedium35 minExactly-once ledger posting consumerMediumDesignStripe styleDesignStripe styleMedium35 minRefund engine with lifecycle awarenessMediumDesignStripe styleDesignStripe styleMedium40 minImmutable ledger correctionsMediumDesignStripe styleDesignStripe styleMedium40 minStored-value wallet with promo expiryMediumDesignPayPal styleDesignPayPal styleMedium35 minAuthorize-then-capture with expiryMediumDesignStripe styleDesignStripe styleMedium40 minTransactional outbox patternMediumDesignDesignMedium35 minStream-batch reconciliationMediumDesignStripe styleDesignStripe styleMedium35 minSession consistency across replicasMediumDesignMeta styleDesignMeta styleMedium40 minWorkflow instance locking and recoveryMediumDesignStripe styleDesignStripe styleMedium40 minLibrary checkout and holdsMediumDesignDesignMedium35 minCoupon redemption serviceMediumDesignDesignMedium35 minEvent ticket check-inMediumDesignDesignMedium35 minInventory trackerMediumDesignDesignMedium30 minMulti-tenant feature flagsMediumDesignDesignMedium40 minCoupon promotion engineMediumDesignShopify styleDesignShopify styleMedium40 minVersioned document storeMediumDesignAmazon styleDesignAmazon styleMedium35 minChat message shardingHardDesignSalesforce styleDesignSalesforce styleHard45 minFinancial ledger replicationHardDesignStripe styleDesignStripe styleHard50 minShopping cart consistency tuningHardDesignAmazon styleDesignAmazon styleHard45 minMVCC snapshot isolationHardDesignOracle styleDesignOracle styleHard50 minChange-data-capture pipelineHardDesignDatabricks styleDesignDatabricks styleHard45 minDistributed append-only logHardDesignDatabricks styleDesignDatabricks styleHard50 minCross-service order transactionHardDesignStripe styleDesignStripe styleHard50 minDesign a financial ledger serviceHardDesignStripe styleDesignStripe styleHard50 min