Multi-AZ notification delivery system using ECS, Lambda, and Fargate to orchestrate push notifications across FCM and APNs at scale. Traffic flows from users through an ALB to ECS Notification Services, which invoke Lambda Fanout Payload Builders to fan out messages to Fargate burst workers that deliver via Firebase Cloud Messaging and Apple Push Notification services. DynamoDB stores user preferences and tokens with cross-AZ replication, while S3 captures delivery logs and A-B testing data, all monitored via CloudWatch. This architecture demonstrates high-availability patterns with auto-scaling compute, multi-provider push integration, and observability for mission-critical notification systems. Fork and customize this diagram on Diagrams.so to adapt notification routing, add SQS queues, or integrate additional push providers.