Demo project showcasing how GAS in Unreal Engine (4.25) can use values from external csv files to initialize and calculate values -

The attribute values will be automatically loaded in and applied to the character on level-up. This means that the data can be kept externally in google spreadsheet files etc and used for balancing without needing to change the core game code. Dynamic gameplay effects are used to apply the stats so no blueprint is necessary. This can be extended to add more csv files for items, abilities etc and have their data be driven through csv files.