DescriptionIn June 2023 more than 15 HPC Centres of Excellence (CoEs) will be covering almost all the scientific domains that use HPC. Some have been running for more than six years and will be in their third edition, while others have just started. Collectively they have a unique view of the current status of HPC codes and the main issues they are facing to run at pre-exascale scales. This minisymposium aims to open a dialog between the different domains to reveal the similarities and differences in optimizing their applications. With presentations from different CoEs, we will identify the common pitfalls and bottlenecks facing the current codes and compare their solutions and approaches. Speakers from four CoEs (ChEESE, PerMedCoE, ESiWACE & CoEC) are invited to summarize the parallel performance and scalability of the application codes of their CoE, and their progress towards exascale on large-scale heterogeneous CPU and GPU computer systems. They are asked to explain how they identify the main bottlenecks and problems to address, as well as to explain the main optimization focus already addressed or planned.