On a GDP(PPP) basis, Russia has the largest economy in Europe, on par with Germany. The Russian economy fell behind the West due to 70 years of communism. Then there was 10 years of nonstop looting and decay during Yeltsin. Putin took Russia out of the gutter in 2000 and has rebuilt it into a middle class country. You can't expect it to be a developed country after all that ruin.

Particularly, the Russian economy was distorted due to the hyper militarization of the Soviet Union during the cold war where 70% of industrial production went towards the military.