I suspect that the person who made this site worked at Amazon. The way they describe SWF makes me think that the author used it when it was in it's prerelease,

I suspect that the person who made this site worked at Amazon. The way they describe SWF makes me think that the author used it when it was in it's prerelease, "Decider" form. The "Flow" version that went onto become the one that was publicly released has a slightly different set of terminology and doesn't expose the use of queues in the same way the Decider version did. I love publicly released version of SWF and think it's a severely underrated product.