Scalable Cross-Channel Notification System

Design a high-throughput notification system supporting Push, SMS, and Email for 100 million daily active users. The system must handle 1 billion notifications daily, respect user-specific preference settings, and ensure reliable delivery despite unreliable 3rd-party provider APIs. Address how you would handle traffic spikes (e.g., breaking news) and ensure at-least-once delivery semantics while minimizing latency.

KafkaRedisPostgreSQLAPI GatewayCircuit BreakergRPCDockerKubernetesAES-256

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Scalable Notification System Design

Design a global-scale notification system capable of handling 1 billion notifications per day across Push, SMS, and Email. The system must support high-priority alerts (e.g., OTPs) with sub-second latency and bulk marketing messages. Your design should address 3rd-party provider reliability, user preference management, rate limiting to prevent spam, and idempotency guarantees. Discuss how you would handle massive traffic spikes and ensure at-least-once delivery for every notification requested.

KafkaRedisPostgreSQLgRPCFCMTwilioSendGridDynamoDBPrometheusGrafana

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Scalable Multi-Channel Notification Engine

Design a high-throughput notification system capable of delivering millions of messages daily across Push, SMS, and Email. The system must handle transactional spikes (e.g., OTPs) with high priority while managing high-volume marketing blasts. Key requirements include at-least-once delivery guarantees, robust retry mechanisms for 3rd party provider failures, user preference management, and strict idempotency to prevent duplicate notifications. Address how the architecture handles provider outages and ensures low-latency delivery during peak loads.

KafkaRedisDynamoDBKubernetesS3API GatewayTwilioSendGridFCMAPNs

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Scalable Multi-Channel Notification System

Design a high-throughput notification system capable of delivering 100M+ messages daily across Push (iOS/Android), Email, and SMS. The system must support message prioritization (e.g., transactional OTPs vs. marketing blasts), handle third-party provider failures gracefully, and ensure at-least-once delivery semantics. Discuss how you would handle global scalability, rate limiting, and delivery tracking.

KafkaRedisNoSQLDynamoDBgRPCAPNsFCMSendGridTwilioLoad BalancerMicroservices

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Scalable Multi-Channel Notification System

Design a highly available and scalable notification system capable of delivering millions of messages across Push (iOS/Android), SMS, and Email. The system must handle varying priorities (e.g., OTP vs Marketing), ensure at-least-once delivery, manage user preferences, and gracefully handle third-party provider failures or rate limits. Detail the architectural choices for decoupling, message persistence, and handling high-concurrency peak loads.

KafkaRedisPostgreSQLCassandraAPNsFCMTwilioSendGridJWTOAuth2gRPCFlink

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Scalable Notification System Design

Design a high-volume notification system capable of delivering 100M+ messages daily across Push, Email, and SMS. The system must handle high-priority transactional alerts (like OTPs) alongside lower-priority marketing campaigns, respect user opt-out preferences, and maintain high availability even during third-party provider outages. Address trade-offs between delivery latency, cost, and reliability.