This caught my eye as well, because the article talks about how big a pain it is to set up & maintain queuing servers, but then provides a solution that simply

This caught my eye as well, because the article talks about how big a pain it is to set up & maintain queuing servers, but then provides a solution that simply isn't as robust. But to be honest, the fact that they open sourced all these libraries and present them front-and-center for anybody interested makes up for that. There isn't any magic going on -- just some straightforward code that leverages language/runtime-appropriate mechanisms to queue up the messages. Its pretty easy to figure out if the solution meets your performance needs when you can see the actual code being run.