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Idempotency, retries & failure handlingHardSDE-3

Placing an order reserves inventory, charges the customer, and books a delivery slot, each in a different service. The delivery booking fails after payment succeeded. How do you design this so the system ends up consistent?

Asked at
AmazonFlipkartSwiggyZepto

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Answer out loud as you would in the room — clarify, give numbers, name the trade-off — then compare with the model answer.

Go deeper

Design an e-commerce platform (Amazon / Flipkart) Lesson: Distributed transactions: 2PC and sagas

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