A waste heat recovery system includes at least two integrated rankine cycle systems coupled to at least two separate heat sources having different temperatures. The first rankine cycle system is coupled to a first heat source and configured to circulate a first working fluid. The second rankine cycle system is coupled to at least one second heat source and configured to circulate a second working fluid. The first and second working fluid are circulatable in heat exchange relationship through a cascading heat exchange unit for condensation of the first working fluid in the first rankine cycle system and evaporation of the second working fluid in the second rankine cycle system. At least one recuperator having a hot side and a cold side is disposed in the first rankine cycle system, second rankine cycle system, or combinations thereof. The at least one recuperator is configured to desuperheat and preheat the first working fluid, second working fluid, or combinations thereof.