expertReal System Design Problems

Design a flash sale system for 10 million users all trying to buy one product at exactly the same second. How do you prevent overselling?

Tests whether you can combine an atomic inventory decrement, a request buffer, and idempotency into one design under extreme concurrent load.

Ready to design this system end to end?

Generate a complete, structured system design answer — requirements, capacity estimation, API design, architecture, database choice, scaling, caching, fault tolerance, security, trade-offs, and more, walked through the way a strong senior engineer would in a real interview.

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