u/ExcitementHealthy834

Building a photo gallery and LazyVGrid was great until I tried scrolling fast through a 50K-

item library. Frame drops, memory spikes during fast flicks, and the prefetch behavior is opaque.

What I tried before giving up on it: - .drawingGroup() — helped on static views, hurt on scrolling -

Manual .id(...) stabilization — no change - Smaller thumbnail decoding — helped some but not

enough - @Observable instead of ObservableObject — minor.

What ended up working: UICollectionView with UIHostingConfiguration cells. Got a stable

60fps. Lost about 200 lines of "pure SwiftUI" pride.

Anyone keep LazyVGrid working at this scale? Curious what I'm missing.

(Project for context: Memories, a Mac→iPhone photo sync app.)

Building a photo gallery and LazyVGrid was great until I tried scrolling fast through a 50K-

item library. Frame drops, memory spikes during fast flicks, and the prefetch behavior is opaque.

What I tried before giving up on it: - .drawingGroup() — helped on static views, hurt on scrolling -

Manual .id(...) stabilization — no change - Smaller thumbnail decoding — helped some but not

enough - @Observable instead of ObservableObject — minor.

What ended up working: UICollectionView with UIHostingConfiguration cells. Got a stable

60fps. Lost about 200 lines of "pure SwiftUI" pride.

Anyone keep LazyVGrid working at this scale? Curious what I'm missing.

(Project for context: Memories, a Mac→iPhone photo sync app.)

Quick PSA after a conversation that surprised me. iCloud Photos is encrypted at rest, but Apple holds the keys unless you explicitly enable Advanced Data Protection (ADP). ADP is opt-in, requires a recovery contact or key, and is unavailable in some regions (UK pulled it earlier this year).

Practical implications: 1. Apple can be compelled to hand over your photos to law enforcement (it has happened, repeatedly — see their transparency reports) 2. An attacker with your Apple ID password gets your photos, even with 2FA in some scenarios 3. Apple-side scanning (CSAM, etc.) is technically possible because the keys are server-side If you turn on ADP, this changes — but the default is "Apple holds the keys." For sensitive photos specifically, the options I've found are: - Turn on ADP and accept the recovery key responsibility - Don't put them in iCloud Photos at all (back up locally) - Use a separate encrypted-photo solution Curious what people here actually do. Not seeing this discussed enough given how many people use iCloud as their photo backup.

(Disclosure: I made an app in this space. Happy to share if anyone asks but I'm not posting to promote.)

Shipping a side project: a Mac → iPhone photo sync app called Memories, written ~95% in SwiftUI / SwiftData. Where SwiftUI won: - Entire onboarding, settings, paywall, album views, timeline - u/Observable coordinators with actor-isolated stores work great once you commit to the model - SwiftData is genuinely fine for ~100K-row metadata stores if you batch writes Where I had to drop to UIKit: - The main photo grid — through 50K thumbnails. Wrote a LazyVGrid chokes once you scroll fast UICollectionView with a UIHostingConfiguration cell. - The zoom-into-fullscreen transition — SwiftUI's matchedGeometryEffect couldn't hit Photos.app-grade smoothness. Custom UIViewControllerTransitioning with a spring driver got there. Everything else is pure Swift concurrency: actors for the store, thumbnail cache, encryption manager, CloudKit downloader/uploader. Happy to answer anything about the SwiftUI/UIKit interop boundaries or the actor model.

The app is available on AppStore with a month of free trial followed by nominal charges of $14.99/year and $1.99/month!!.

https://preview.redd.it/k0zgp4wmjhyg1.jpg?width=460&format=pjpg&auto=webp&s=cd2701b9da7361739a92a85bcb8ed0dc7222d7ec

https://preview.redd.it/kcud66wmjhyg1.jpg?width=460&format=pjpg&auto=webp&s=7b56a30f0f6eaf64bee27019d9d1a5ac4b06c0f4

https://preview.redd.it/q4yvx5wmjhyg1.jpg?width=460&format=pjpg&auto=webp&s=7a6c9a83f51f996e8a41b0f1e40cd55a7e5442f1

https://preview.redd.it/wpmcr5wmjhyg1.jpg?width=460&format=pjpg&auto=webp&s=e1c39b1bae91ded10765930e4a4734a47e3ec39d

https://preview.redd.it/0z5emrtnjhyg1.jpg?width=460&format=pjpg&auto=webp&s=69352b82793eb058b70c83891bbfa9256f8f2b05

Shipping a side project: a Mac → iPhone photo sync app called Memories, written ~95% in SwiftUI / SwiftData. Where SwiftUI won: - Entire onboarding, settings, paywall, album views, timeline - u/Observable coordinators with actor-isolated stores work great once you commit to the model - SwiftData is genuinely fine for ~100K-row metadata stores if you batch writes Where I had to drop to UIKit: - The main photo grid — through 50K thumbnails. Wrote a LazyVGrid chokes once you scroll fast UICollectionView with a UIHostingConfiguration cell. - The zoom-into-fullscreen transition — SwiftUI's matchedGeometryEffect couldn't hit Photos.app-grade smoothness. Custom UIViewControllerTransitioning with a spring driver got there. Everything else is pure Swift concurrency: actors for the store, thumbnail cache, encryption manager, CloudKit downloader/uploader. Happy to answer anything about the SwiftUI/UIKit interop boundaries or the actor model.

The app is available on AppStore with a month of free trial followed by nominal charges of $14.99/year and $1.99/month!!.

https://preview.redd.it/cqdhky7mihyg1.jpg?width=460&format=pjpg&auto=webp&s=ab584c58e6a97c18d95375a0a80aefcdf23474f0

https://preview.redd.it/ovs5sdamihyg1.jpg?width=460&format=pjpg&auto=webp&s=993e424200c2bf7daa7cf681bc0fb61e505d2993

https://preview.redd.it/msi50bamihyg1.jpg?width=460&format=pjpg&auto=webp&s=d659d7b69411dbaaffd33d7c63a3f832536918a9

https://preview.redd.it/2uw09famihyg1.jpg?width=460&format=pjpg&auto=webp&s=971ce6e3ed3146fa1872422745e4c8c7de6bacb7

https://preview.redd.it/8vh3ih9nihyg1.jpg?width=460&format=pjpg&auto=webp&s=f2115c38e3486b926b9d34538617380fc4e9123f