Amazon SNS enables businesses to send messages or notifications directly to users with SMS text messages to over 200 countries, mobile push on Apple, Android, and other platforms or email (SMTP).
AWS Lambda is an event-driven, serverless computing platform provided by Amazon as a part of Amazon Web Services. It lets clients run code without provisioning or managing servers.
Amazon Simple Queue Service (SQS) is a fully managed message queuing service that enables developers to decouple and scale microservices, distributed systems, and serverless applications.
AWS AppSync is a fully managed service that makes it easy to develop GraphQL APIs by handling the heavy lifting of securely connecting to data sources like AWS DynamoDB, Lambda, and others.