My proposal, is to divide Ukraine up into three parts.
Western Ukraine - Based in L’viv, the part of the Ukraine, that traditionally belonged to Austria-Hungary and Poland. Could be eligible for NATO and EU membership. Potentially also become a member of the Visegrad Group, along with Poland, Czechia, Slovakia, Hungary, etc.
Ukraine - Based in Kiev, would be neutral, NATO and Russia will not be allowed to base troops there, or join any such alliance. Basically serves as a buffer state.
Eastern Ukraine (Donbass) - Free to join Russia or become aligned with Russia.
I think Putin would take that deal if anybody would offer it.