#04Scalable Notification System
4 / 20
WorkflowCanvas
Uber logoUber System
MediumProduct Systems
30–45 min

Scalable Notification System

Architect a multi-channel notification engine supporting iOS APNS, Android FCM, SMS (Twilio), and transactional emails with priority routing and deduplication.

Scale & Traffic10M+ notifications/day · Global delivery
Monthly Cloud Budget$2,500/month
Latency Target (P99)< 50ms Realtime SLA
Availability SLA99.99% Multi-AZ Active
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System Requirements

  • Multi-channel fan-out: Push, SMS, Email, and In-App inbox
  • Priority tiers: OTP & emergency alerts bypass promotional queues
  • User preference filtering and quiet hour rate limiting
  • Idempotent delivery preventing duplicate notifications

Graded Constraints

01Total cost under $2,500/month
02Dedicated message queue (Kafka / RabbitMQ / Queue) to prevent backpressure
03Worker pool / microservices for provider dispatch
04Third-party external API integration nodes for gateways (APNs/FCM/Twilio)

Ready to design?

Open this challenge in the interactive system design playground and satisfy all architecture constraints.

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Scalable Notification System — System Design Problem | Mimir Nest