[Groxx]

"Every sufficiently-complex system eventually includes a badly-implemented email / lisp / kafka (/zmq/etc)"

Something like a combination of Greenspun's Tenth Rule[1] and Zawinski's Law[2]. Plus whatever would include your queueing system of choice.

Though honestly I've seen more bad queues than emails or lisps. By an order of magnitude or two.

[1]: https://en.wikipedia.org/wiki/Greenspun%27s_tenth_rule [2]: https://en.wikipedia.org/wiki/Jamie_Zawinski#Zawinski's_Law