Overview of the WLCG strategy towards HL-LHC computing - April 2020 LHCC review

This document gives an overview of the WLCG strategy towards the HL-LHC computing challenge. It focuses on the aspects related to the organisation and the facilities, but also touch bases on technology evolution, software and services. The document served as input for the HL-LHC computing review initiated by the CERN LHCC in April 2020