Today there was a failure in the cloud services of Apple Developer.
The incident has been going on for over an hour.
Third-party developers around the world have become partially or completely inaccessible to Apple services: App Store - TestFlight, App Store Connect, including App Processing and App Upload, Content Delivery, Xcode Cloud.
Apple explained that it is aware of the problem and is working on a solution to restore the performance of all services affected by the failure.