On every successful login, the Datadog Android application calls FirebaseCrashlytics.setUserId with the signed-in user's Datadog UUID — a stable per-user identifier that is meaningful inside Datadog. This associates the Datadog user UUID with the device's Firebase installation ID on Google's backend. Separately, uncaught exceptions are forwarded to Firebase Crashlytics via recordException, attaching stack traces (which may include internal class names, package names, in-flight data referenced by crash frames, and any breadcrumbs) to the same user UUID. No visible consent gate or opt-out for Crashlytics tagging was identified in the reviewed code paths. No email, name, or organization data is forwarded to Crashlytics in the reviewed paths.