Syncing large CoreData databases with CloudKit and CKSyncEngine

This month we'll be talking about a new framework I've been working on called Mistral, a soon-to-be open-source Swift library that bridges CoreData and CloudKit using CKSyncEngine. Mistral lets you adopt protocols on your managed objects to selectively sync attributes and relationships, with support for CK assets, cross-model sync triggers, and pre- and post-import hooks — all built with Swift concurrency. We'll walk through the architecture and see it in action with Mimir, a podcast app where Mistral replaced a more complex dual-CoreData-store syncing setup. I'll also touch on how AI tooling helped me push through the final stages of development. Whether you've been curious about CKSyncEngine or you're looking for more control over your CloudKit sync, this talk is for you.