Mobile crash reporting

The mobile golden signal is crash-free users per release. It needs three things from the app: a crash SDK, the release (version + build) and environment on every event, and session tracking — without sessions a tool knows how many crashes there were but not out of how many users.

Sentry

• iOS (sentry-cocoa, Swift Package Manager): SentrySDK.start { o in o.dsn = …; o.releaseName = "\(bundleId)@\(version)+\(build)"; o.environment = "production"; o.enableAutoSessionTracking = true } at app launch. Upload dSYMs in the release build (sentry-cli debug-files upload or the Fastlane sentry_debug_files_upload action) or crashes arrive unsymbolicated.
• Android (io.sentry:sentry-android + the io.sentry.android.gradle plugin): DSN, release and environment in the manifest <meta-data> or SentryAndroid.init; the Gradle plugin uploads the R8/ProGuard mapping per build.
• React Native: @sentry/react-native (its wizard wires both native projects and source maps). Flutter: sentry_flutter with SentryFlutter.init, and --split-debug-info symbols uploaded.
• The DSN is not a secret, but the sentry-cli auth token used for uploads is: a CI secret, never in the repository.

Firebase Crashlytics

• iOS: FirebaseCrashlytics via SPM, FirebaseApp.configure(), and the upload-symbols run script phase for dSYMs.
• Android: com.google.firebase:firebase-crashlytics and the com.google.firebase.crashlytics Gradle plugin (mapping upload on release builds).
• Crashlytics takes the version from the app itself; set the environment as a custom key (Crashlytics.crashlytics().setCustomValue("staging", forKey: "environment")) and keep debug builds out (setCrashlyticsCollectionEnabled(false) there).
• Crash-free users is reported by the Firebase console; Google Play's Android vitals (and App Store Connect's metrics) give the store-side view a store data source reads.

Desktop (Electron)

@sentry/electron in both the main and renderer processes, release from app.getVersion(), native crash minidumps enabled.

In the task

• One SDK, initialised before anything else at launch; no personal data in breadcrumbs (strip request bodies, emails, tokens).
• Acceptance criteria: "Given a build of this release crashes on a test device, then the crash appears in <Sentry|Crashlytics> symbolicated, tagged with this version and environment"; "Given the app is opened, then a session is recorded for this release."
• A store build has to ship before any of this is visible: say so, and tell the person which data source (Sentry, Google Play vitals, App Store metrics) to add so mobile.crash_free_users can be bound.