Everything is Shared (And That’s the Problem)

A story about SwiftUI dependency injection, singletons, and the bug that only shows up when you have two windows open… Everything is Shared (And That’s the Problem) A story about SwiftUI dependency injection, singletons, and the bug that only shows up when you have two windows open… Michael Long in Level Up Coding   ∙   October 16, 2026   ∙   10 min read   ∙   View on Medium Demo Application Image by Michael Long Most dependency injection systems assume your app has exactly one window. One process, one screen, one object graph. And a single global container sitting at the bottom of it all, handing out services to anyone who asks. It’s the assumption baked into pretty much every DI library out there, including mine. And it was a reasonable assumption. Until it wasn’t. I found that out the hard way while working on SceneGeometry for Runes, my open source collection of Swift and SwiftUI utilities. Let’s take a look at what happened and what we can do to fix it. The Duo Apple recently announced… Continue reading This is a member-only story and can only be read on Medium. Sent to sikubaycom.s3cr3tz@blogger.com by Michael Long on Medium Unsubscribe from this writer's email notifications Manage your email settings 3500 South DuPont Highway, Suite IQ-101, Dover, DE 19901 Careers·Help Center·Privacy Policy·Terms of service