Probably the most iconic weapon associated with technical trucks is the Zu-23 double barrel 23mm AA gun. What I’ve found fascinating is the basic reason why.

There’s an interesting convergence here. First off, yes, it’s a very good medium autocannon that’s cheap and common enough that even the poorest can get them en masse. Its use in battle is obvious. Yet its its dimensions more than anything else that puts it in the goldilocks sweet spot.
On one hand, its big and heavy enough that it needs to be mounted on a vehicle to move quickly. But it’s light enough that it can be effectively operated from the back of a pickup truck. Function followed form.