This is the second part of CoS-2 School on HPC architectures and numerical methods and will develop the ideas presented in the first part of CoS-2 in more detail. The focus will be on three “case studies” of large-scale problems and existing code bases that will be review in some detail. These code bases will be chosen from the research areas of the project. Successful completion of any one of the programmes will be worth 5 ECTS accreditation units. The School will offer 15 extra positions for Students and Researchers that are not HPC-LEAP fellows.