Existing APK and AAB
ProductionAPK is commonly installable; AAB is the Play publishing bundle. Both carry an immutable package name and version identity.
What you need
A valid signed APK or AAB, matching Google Play application and service-account access.
What LaunchLayer does
Inspects signature and manifest metadata, enforces package-name matching, preserves track mapping, validates version information, uploads, and monitors Google processing.
What you still need to do
Use an increasing version code, choose the intended Play track, complete console declarations, and manage rollout or publication.
Common problems
Unsigned or invalid artifacts, wrong package name, duplicate version code, insufficient Play permissions, wrong track, or processing delays.