Design a notification system that receives notification requests and sends notifications to users through phone or email.
The system should be scalable, highly available, and fault tolerant.
You may discuss the API and database schema in detail, or start with the high-level infrastructure components.
This problem is a system design question for a notification platform. A strong solution separates request ingestion, queueing, worker processing, and provider delivery to achieve scalability and fault tolerance. The design should also track notification status in a database for auditing, retries, and observability.
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