AWS AppSync is a managed GraphQL service that simplifies application development by letting you create a flexible API to securely access, manipulate, and combine data from one or more data sources. Today we’re releasing two important features to improve performance and consistency for applications using AppSync APIs. 

from Recent Announcements: https://aws.amazon.com/about-aws/whats-new/2019/11/aws-appsync-adds-server-side-caching-and-dynamodb-transactions-support-for-graphql-apis/