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Replicate production to the test instance to get a clone of production environment
Capture screenshots on the test instance before the upgrade is made
Perform upgrades on test
Verify screenshots to capture any regressions resulting from upgrades
Verifying any other functionality that may be affected by the upgrade. Important: due to deficiency in automatic testing for certain features (such as custom plugins, i.e. QA Plugin), these features need to be tested manually to ensure the stability of the system
Perform adjustments until screenshot tests pass and any manual testing issues are resolved
Perform the same set of upgrades on production
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