Had my Core Data sync framework, Ensembles (https://ensembles.io), pretty much in maintenance mode. With Apple moving on to SwiftData, didn't seem any point to modernizing the 15 year old ObjC codebase. But I had the thought to give Claude a shot at it, and in 2 days I've got a complete port: Swift 6, structured concurrency instead of OperationQueue. Even adding a bunch of new backends (Box, pCloud, S3). Will make it available as Ensembles 3 to subscribers soon.
Ensembles Core Data Sync Framework

Ensembles is a sync framework for Core Data apps. Works with iCloud, Dropbox, and any backend you choose.

Ensembles Core Data Sync Framework
Spent a few more hours with Claude, looking at whether Ensembles could be made to work with SwiftData. Seems it is relatively straightforward. In short: E3 should be capable of syncing Core Data AND SwiftData projects via a multitude of backends (CloudKit, Box, Dropbox, even peer-to-peer). If anyone has a backend they think would be good to add, let me know. It's best if it has a swift package, but can also use REST etc.