"Simple, mobile and effective," the military from the 28th Mechanized Brigade say about this vehicle with a 30-mm automatic grenade launcher AGS-17 "Plamya" on top of it. And it looks from the video, that it was not just placed on the buggy, but welded to the roof for better stabilization. However, the vehicle is lightweight itself, so the gunner has to fire in short sequences.
The crew of this improvised "combat vehicle" is likely two people, as shown in the footage. And combined with the drone reconnaissance and adjust fire provided by scouting squads, such a buggy can shell enemy positions up to 1.7 km away.
Read more: Ukraine’s Marines Describe Their Mastiff Armored Vehicle Experience
This handcrafted creation is far from the only Ukrainian "invention". Skilled with shoot-and-scoot guerilla tactics, Ukrainian forces have adapted numerous highly mobile vehicles for carrying lethal armament. We have already seen units on quad bikes carrying "Stugna-P" ATGMs, pickups with heavy machine guns and rocket launchers taken from russian helicopters.

And the most recent Ukrainian "patents": buggy groups withFrench "Milan" ATGMs and American FGM-148 Javelins, heavy anti-tank gun mounted on an armored MT-LB vehicle.
Also, read more about the AGS-17 grenade launcher mounted on this buggy in this article.
Read more: The Jets for Ukrainian Air Force Have Already Been Decided And It Is Not the F-16: Tips From the Pentagon And Copenhagen