https://en.wikipedia.org/wiki/Buk_missile_system
a very good technology that the Soviet Union developed which punches above its weight in situations like the Ukraine war because the mobile radars are hard to suppress with these methods
https://en.wikipedia.org/wiki/Suppression_of_Enemy_Air_Defen...
I have seen a huge number of Buks in various conditions in video footage from the war, one of them was scurrying around the 'suburban' areas of Kiev. I wouldn't be surprised if some of the early missile hits on residential buildings were something like this that failed to lock on
https://en.wikipedia.org/wiki/Anti-radiation_missile
Ukraine has a lot of Buks, it has a handful of these too
https://en.wikipedia.org/wiki/S-300_missile_system
on paper those are better than the Buk but Ukraine doesn't have so many and I think the Buk is a "cheap and cheerful" convivial weapon like the AK-47 that does great when exported.
(Both the Buk and S-300 are a lot like the US Patriot missile system in that they are comprised of a number of mobile units such as command posts, radar, missile launchers, etc. The Buk however has a configuration where the radar and missile launcher are colocated on the same vehicle and I'd guess that configuration works really well under rough conditions with less trained crews.)