A process for the catalytic cracking of hydrocarbons, comprising: regenerating a spent catalyst comprising a first cracking catalyst having a first average particle size and density and a second cracking catalyst having a second average particle size and density in a catalyst regeneration vessel to form a regenerated catalyst comprising the first cracking catalyst and the second cracking catalyst, wherein the average particle size of the first cracking catalyst is less than the average particle size of the second cracking catalyst and wherein the first cracking catalyst comprises a Y-type zeolite catalyst and the second cracking catalyst comprises a ZSM-5 catalyst; contacting in co-current flow a first hydrocarbon feed with a first portion of the regenerated catalyst in a riser reactor to produce a first effluent comprising a first cracked hydrocarbon product and a spent mixed catalyst fraction; feeding a second portion of the regenerated catalyst to a countercurrent flow reactor; concurrently in the countercurrent flow reactor: separating the first cracking catalyst from the second cracking catalyst based on at least one of density and particle size; contacting in countercurrent flow a second hydrocarbon feed with the second cracking catalyst to produce a second cracked hydrocarbon product; recovering a second effluent from the countercurrent flow reactor comprising the second cracked hydrocarbon product and the first cracking catalyst; and recovering a third effluent comprising spent second catalyst; feeding the first effluent and the second effluent to a disengagement vessel to separate the spent mixed catalyst fraction and the separated first cracking catalyst from the first and second cracked hydrocarbon products; and feeding the separated catalysts from the disengagement vessel to the catalyst regeneration vessel as the spent catalyst. regenerating a spent catalyst comprising a first cracking catalyst having a first average particle size and density and a second cracking catalyst having a second average particle size and density in a catalyst regeneration vessel to form a regenerated catalyst comprising the first cracking catalyst and the second cracking catalyst, wherein the average particle size of the first cracking catalyst is less than the average particle size of the second cracking catalyst and wherein the first cracking catalyst comprises a Y-type zeolite catalyst and the second cracking catalyst comprises a ZSM-5 catalyst; contacting in co-current flow a first hydrocarbon feed with a first portion of the regenerated catalyst in a riser reactor to produce a first effluent comprising a first cracked hydrocarbon product and a spent mixed catalyst fraction; feeding a second portion of the regenerated catalyst to a countercurrent flow reactor; concurrently in the countercurrent flow reactor: separating the first cracking catalyst from the second cracking catalyst based on at least one of density and particle size; contacting in countercurrent flow a second hydrocarbon feed with the second cracking catalyst to produce a second cracked hydrocarbon product; recovering a second effluent from the countercurrent flow reactor comprising the second cracked hydrocarbon product and the first cracking catalyst; and recovering a third effluent comprising spent second catalyst; separating the first cracking catalyst from the second cracking catalyst based on at least one of density and particle size; contacting in countercurrent flow a second hydrocarbon feed with the second cracking catalyst to produce a second cracked hydrocarbon product; recovering a second effluent from the countercurrent flow reactor comprising the second cracked hydrocarbon product and the first cracking catalyst; and recovering a third effluent comprising spent second catalyst; feeding the first effluent and the second effluent to a disengagement vessel to separate the spent mixed catalyst fraction and the separated first cracking catalyst from the first and second cracked hydrocarbon products; and feeding the separated catalysts from the disengagement vessel to the catalyst regeneration vessel as the spent catalyst.