note that this should be less of an issue for real users because Play Store collects stack trace profiles from real-world usage and AOT compiles the performance-critical part of the app. it's mostly highly visible to developers writing a new app and deploying locally, so we're considering adding an AOT compile list for known Compose hot functions to Android Studio "Run" workflow

to confirm that this is indeed JIT and not something else, you can force a full AOT compile of your app with the command:

adb shell cmd package compile -r [install|bg-dexopt] pkg_name

we’re considering adding an AOT compile list for known Compose hot functions to Android Studio “Run” workflow

Would love to see this exposed for command-line builds as well, both for local development as well as running UI tests. We also have a bit of a strange use case, we deploy android apps to custom devices which have storage restrictions that prevent us from using the

speed

filter on all the apps indiscriminately, but we could probably use a specific profile just for compose code.

right, your command-line build use case sounds reasonable. we were talking about making a "specific profile just for compose code" by doing something like taking the intersection of profiles of 3 of our sample apps. aside from your storage restriction use case, the main reason we'll definitely want that is for build speed

@louiscad for what it's worth, on pre-Android-10, there is another mechanism of overnight on-device

dex2oat

compile based on the user's local profile of recently installed apps

I agree it's "kinda uncomfortable" to have performance based on various heuristic systems. Compose-team is keeping an eye on this and we'll keep working on both improving the coverage of the heuristics and adding new 100% consistent mechanisms where it makes sense

AOT-vs-JIT is a very tricky tradeoff that Android has been circling and trying different approaches on since the beginning. In the past the tradeoff affected install time vs loading time; now with Compose distributing more view-layer code as part of the APK, initial scrolling perf enters the tradeoff space as well, so it's an opportunity to revisit and make sure we're striking the right balance