I didn't mean queues in general, my bad. I meant, as you pointed out, enterprise grade queuing systems: there are lot of stuff going on there that are not exactly the stuff one learns in the Data Structures 101 course.

> And the implications of rate in > rate out is pretty obvious for anyone that's ever had a clogged sink.

Well, many developers I know are in their early 20s. I'm not sure they ever had to deal with clogged sinks :)