If you want to carry messages across the internet SQS et al is fine. But within the same system, e.g. in the same computer, or cluster, it makes much more sense

If you want to carry messages across the internet SQS et al is fine. But within the same system, e.g. in the same computer, or cluster, it makes much more sense to use something like this rather than something like SQS. Different tool, different job.