Amazon AppFlow supports new options for updating records
Amazon AppFlow, a fully managed integration service that enables customers to securely transfer data between AWS services and cloud applications, now supports the option of upserting records in destinations, in addition to already supported option of inserting records. This feature is now available when Salesforce is selected as the destination. The upsert operation updates existing records in Salesforce if they exist; otherwise, it inserts the data as new records. Customers can now insert, or upsert up to 500 MB of data in Salesforce in a single flow run.
Source:: Amazon AWS