Starting today, a number of Amazon Aurora features like invoking an AWS Lambda function synchronously, hot row contention, Backtrack, and hash joins, will now be available on the MySQL 5.7-compatible edition of Aurora to improve performance and manageability. The MySQL 5.7-compatible edition of Amazon Aurora already offers enhancements such as JSON support, spatial indexes, and generated columns.
https://aws.amazon.com/about-aws/whats-new/2019/11/amazon-aurora-mysql-57-expands-list-of-supported-features-to-improve-performance-and-manageability/