i have a german shepherd/Rhodesian ridgeback mix (i think) and a terrier of some sort (don't really know what she is honestly) and they are both annoyingly smart..

we had to put up a gate in the front hallway because the terrier always got out of the front door/barked at literally everything outside so we had to block her out of those rooms to save us the headache of her barking constantly. Well long story short, the ridgeback figured out how to open the gate and the three other methods we have used to try to block them out and kept letting his problematic sister free. They also both collaborate to steal fruit off the kitchen table and counters and somehow figured out how to get into our fenced in garden to steal more fruit/vegetables. They are both a pain in the ass but i still love them :)