Amazon DynamoDB Time to Live (TTL) allows you to define a per-item timestamp to determine when an item is no longer needed. Shortly after the date and time of the specified timestamp, DynamoDB deletes the item from your table without consuming any write throughput.  

https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/TTL.html#:~:text=Amazon%20DynamoDB%20Time%20to%20Live,without%20consuming%20any%20write%20throughput.