At the AWS/Arm Cloud Hackathon, LLNL’s Todd Gamblin and Greg Becker discussed (video, 31:42) the essential skills and concepts needed to understand how to create and deploy Spack recipes to build scientific codes. The Hackathon was held July 12-16 and aimed to assemble the HPC community around a common goal of beginning the porting, testing, and tuning processes for dozens of codes to use Arm-based processors.