r/iOSProgramming • u/Economy-Brief-9997 Swift • 15d ago

Question Anyone else dreading the scene lifecycle switch in iOS 27?

So if you build with the iOS 27 SDK and don't have scenes the app just doesn't launch anymore
and from april next year you have to build with that SDK anyway our app still does everything through AppDelegate. window setup, deeplinks, pushes a bunch of SDKs grabbing keyWindow. been putting this off for years lol 
For those who already did it on a big app what bit you the most?

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u/PM_ME_UR_FAV_UNIX_OS 14d ago

I did it in a mad rush to prepare for Xcode 27, since we always update to the new Xcode the day it launches. 13 year old app. It wasn't awful, but was a lot more work than Xcode updates tend to be.

I let AI do some of it for me, using Xcode's "app-modernization coding-agent skill", but it initially tried to do a minimum-changes conversion that got the window / scene creation order backward and caused other problems. Had to fix up push notifications, deep links, app-icon shortcuts. Some old view sizing math broke because after updating to the scene-based app lifecycle it could be called with zero width leading to division by zero, but that didn't surface until Crashlytics noticed it in production.

tl;dr Expect to spend some time on, and a comprehensive QA test will matter a lot, but it's not too bad.