Well it all depends on how you're expecting your types to be extended. I'm not sure what TypeScript's support for interfaces is like but it might make sense to

Well it all depends on how you're expecting your types to be extended. I'm not sure what TypeScript's support for interfaces is like but it might make sense to have interfaces for both (just in case you ever have a product that's both physical and digital). Tagged unions might get a bit messy if you ever need to extend them, but sometimes you simply have some source / sink of data that requires a variant type.