advancedReal System Design Problems

Design a notification system — push, SMS, email — at 100M users/day.

Tests whether you can design multi-channel fanout with retries, rate limiting per user, and provider failover.

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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