>>mpweih+(OP)
One important drawback of SQS is that it's eventually consistent, you can read the same message twice from different workers. Nevertheless we keep using it with additional checks when it's critical, it's still the cheapest solution by maintenance.
FIFO (First-In-First-Out) queues are designed to enhance messaging between applications when the order of operations and events is critical, or where duplicates can't be tolerated