I think that the Ukrainian military strategically has been mostly intelligent and technically well prepared. When Putin stated over and over that he would not invade Ukraine, they did not prepare for the best case, but for the worst scenario and they were right.
Ukraine has been actively preparing for its attack on the Donbass all winter. There was a lot of talk about the possibility of a Russian invasion, but however, it turned out to be a complete surprise for Ukraine, NATO intelligence simply overslept it. The genius of Putin's strategy lies precisely in the fact that, according to the military canons current as of February 2022, it was technically impossible - too small forces participated in Russian military exercises near the border with Ukraine and NATO intelligence did not take this threat seriously. This gave Russia at the start of the operation the staggering advantage of a surprise strike from which Ukraine still seems to be in shock.