IRIS and UNAVCO are national repositories for seismic and geodetic repositories with international communities of scientists contributing and using data to understand the dynamic earth system that have operated independently for many decades. They are currently planning a merger in the next several years and are moving data and services into the cloud as part of that process. The repositories are currently in domain specific formats (mostly miniSeed and RINEX) so this migration includes changes in format as well. XArray compliant netCDF4/HDF5 is a leading candidate for the target format with discovery and access driven by metadata in a relational database. I will present some ideas and questions for the Pangeo community to help us understand and incorporate best practices.