Yes -- you can bulk upload items in DSpace! I personally start by collecting my files and metadata, and then I use SAFBuilder (
https://github.com/DSpace-Labs/SAFBuilder) to turn my files and metadata into Simple Archive Format zip files -- the creator, James Creel, did a workshop on using SAFBuilder at the 2024 North American User Group Meeting and
shared the slides in the wiki. Then I use the UI to upload my content -- I do a "validate only" run first, check the log for any errors, and then run the actual upload. I usually limit myself to 100 items at a time.