AWS Simple Notification Service

Collaborative Infrastructure as Design: Collaboratively manage infrastructure with your coworkers synchronously sharing the same designs.

Message fanout: Each account can support 100,000 Standard topics and each topic supports up to 12.5M subscriptions.
Amazon SNS supports VPC Endpoints (VPCE) via AWS PrivateLink.
Amazon SNS mobile notifications make it simple and cost effective to fan out mobile push notifications to iOS, Android, Fire, Windows, and Baidu devices.