A process for converting a high-boiling hydrocarbon feedstock into lighter boiling hydrocarbon products, said lighter boiling hydrocarbon products being suitable as a feedstock for petrochemicals processes, said converting process comprising the following steps of: feeding a hydrocarbon feedstock having a boiling point of > 350 deg Celsius to a cascade of hydrocracking units comprising at least three hydrocracking units, wherein the at least three hydrocracking units are preceded by a hydrotreating unit, wherein the bottom stream of said hydrotreating unit is used as a feedstock for said first hydrocracking unit, the bottom stream of said first hydrocracking unit is used as a feedstock for said second hydrocracking unit, the bottom stream of said second hydrocracking unit is used as a feedstock for said third hydrocracking unit, wherein the pressure for the first hydrocracking stage is 150 to 200 Barg operating pressure, the pressure for the second hydrocracking stage is 100 to 200 Barg operating pressure and the pressure for the third hydrocracking stage is 100 to 300 Barg operating pressure, wherein the bottom stream of a hydrocracking unit as a feedstock for a subsequent hydrocracking unit is such that said feedstock for a subsequent hydrocracking unit is heavier than the feedstock of a previous hydrocracking unit in the cascade of hydrocracking units, wherein the process conditions in each hydrocracking unit(s) are different from each other, in which the hydrocracking conditions from the first to the subsequent hydrocracking unit(s) increase from least severe to most severe, wherein the temperature prevailing in said hydrotreating unit is higher than in said first hydrocracking unit, wherein the temperature in said hydrotreating unit is in the range 300 to 400 °C and the temperature in said first hydrocracking unit is in the range 280 to 300 °C, wherein the temperature in the cascade of hydrocracking units increases, wherein the temperature prevailing in said third hydrocracking unit is higher than in said hydrotreating unit, wherein the temperature in said third hydrocracking unit is in the range 440 to 490 °C, and processing the lighter boiling hydrocarbon products from each hydrocracking units as a feedstock for one or more petrochemicals processes. feeding a hydrocarbon feedstock having a boiling point of > 350 deg Celsius to a cascade of hydrocracking units comprising at least three hydrocracking units, wherein the at least three hydrocracking units are preceded by a hydrotreating unit, wherein the bottom stream of said hydrotreating unit is used as a feedstock for said first hydrocracking unit, the bottom stream of said first hydrocracking unit is used as a feedstock for said second hydrocracking unit, the bottom stream of said second hydrocracking unit is used as a feedstock for said third hydrocracking unit, wherein the pressure for the first hydrocracking stage is 150 to 200 Barg operating pressure, the pressure for the second hydrocracking stage is 100 to 200 Barg operating pressure and the pressure for the third hydrocracking stage is 100 to 300 Barg operating pressure, wherein the bottom stream of a hydrocracking unit as a feedstock for a subsequent hydrocracking unit is such that said feedstock for a subsequent hydrocracking unit is heavier than the feedstock of a previous hydrocracking unit in the cascade of hydrocracking units, wherein the process conditions in each hydrocracking unit(s) are different from each other, in which the hydrocracking conditions from the first to the subsequent hydrocracking unit(s) increase from least severe to most severe, wherein the temperature prevailing in said hydrotreating unit is higher than in said first hydrocracking unit, wherein the temperature in said hydrotreating unit is in the range 300 to 400 °C and the temperature in said first hydrocracking unit is in the range 280 to 300 °C, wherein the temperature in the cascade of hydrocracking units increases, wherein the temperature prevailing in said third hydrocracking unit is higher than in said hydrotreating unit, wherein the temperature in said third hydrocracking unit is in the range 440 to 490 °C, and processing the lighter boiling hydrocarbon products from each hydrocracking units as a feedstock for one or more petrochemicals processes.