Great article! This is theoretical but have you ever considered pushing a message to SQS and then having a SNS and Lambda subscribe to the event? That way the lambda is only invoked when there is new message in SQS. The only reason why I still want to use SQS rather than DynamoDB is that it now supports at rest encryption in a few zones. Once initiated the lambda can poll the SQS queue for the next 30 seconds until the queue is clear.