LUMI is a new upcoming EuroHPC pre-exascale supercomputer with peak performance a bit over 550 petaflop/s. Many countries of LUMI consortium will have access on this system among other users. It is known that this system will be based on the next generation of AMD GPUs and this is a new environment for all of us. In this talk we discuss the AMD ecosystem, ROCm, which is open source and available on github. We present with examples the procedure to convert CUDA codes to HIP, among also how to port Fortran codes with hipfort. We discuss the utilization of other HIP libraries and we demonstrate performance comparison between CUDA and HIP on NVIDIA GPUs. We explore the challenges that scientists will have to handle during their application porting and also we provide step by step guidance.