You could say soviets did all the WW2 heavy lifting, starting with

https://en.wikipedia.org/wiki/Kama_tank_school

https://en.wikipedia.org/wiki/Lipetsk_fighter-pilot_school

https://en.wikipedia.org/wiki/Tomka_gas_test_site and

and culminating in https://en.wikipedia.org/wiki/Molotov%E2%80%93Ribbentrop_Pac...

lol, not really. First of all, the kind of "heavy lifting" the Soviet Union did was agreeing with Nazi Germany to partition Poland and subsequently raiding it together from both sides (Molotov–Ribbentrop Pact) – never forget they were allies until Hitler turned on them.

The "heave lifting" you refer to was mostly paid for and organized by the Lend-Lease Act. There would have been no eastern front without it.