I'm pretty new to domain driven design, but I'm interested in its benefits. Currently, I'm working on a C# application that will run on a one-off basis to import data from many different spreadsheets (over 100) into a cloud-based system. There is no UI, and there is no user interaction. There's simply a target folder the program reads from until it's read all spreadsheets and then it stops. The application is essentially reading domain objects from one persistence type (spreadsheets) and using the use cases in the application layer to save them to another persistence type (cloud system).
I describe all my objects in the domain layer, lay out interactions with the cloud system in the persistence layer, and specify the queries and commands in the application layer. Currently, I don't have a presentation layer; do I need one in an application with no UI? Additionally, where should the actual code that reads from the spreadsheets go? I can't figure out if I need an infrastructure layer, a presentation layer, or if I should just put this in the application or persistence layers.