Shortly after the release of macOS Big Sur back in 2020, Apple faced widespread server outages. The outage affected macOS installations, iMessage, Apple Pay, and most notably: the notarization service. This meant that users had major issues opening apps, revealing a flaw in how Apple handles app verification on the Mac.
Background
For some context, your Mac does a couple verification checks whenever you launch an app. One of the checks is to verify the app isn’t malware, and the other is to make sure the developer certificate associated with the app is still valid. These checks are meant to keep users safe, and are widely referred to as App Notarization.
Normally, if you’re using your Mac offline, the checks just fail and your app will launch normally. However, when this server outage occurred, macOS was still attempting to check the servers rather than just failing. This resulted in apps taking a painful amount of time to launch.
Apple’s promised…
Source 9to5mac.com