But does Russia have any experience building really big aircraft?
Well, the AN 225 is the worlds largest airplane; but its Ukrainian, with Russian components. One reason why they still want Ukraine...
United Aircraft Corporation merges all the old Soviet design bureaus. This includes Tupolev - built TU160, worlds largest combat aircraft; Ilyushin with the IL96 commercial aircraft; also Yakovlev and Sukhoi with various military and civilian jets.
So yeah, with Tupolev and Ilyushin they have the experience. Can they make a quality product with long term support? We’ll see.