What should you test before a release?
Start with login, payments, permissions and the tasks users do every day.
List the failures that matter most
A broken payment flow needs more attention than a small visual issue. Identify the features that could lose data, charge the wrong amount or give someone access they should not have.
Use the right kind of test
Use unit tests for business rules and integration tests for APIs and database behaviour. Add end-to-end tests for important user flows. Test manually to find confusing interactions and problems your scripts miss.
Fix tests that keep crying wolf
A flaky test wastes time and gets ignored. Check for timing problems, shared test data and external dependencies. Keep the test suite small enough to maintain and useful enough that people trust it.
Check how you would recover
Review unresolved bugs and performance results before releasing. Confirm that you can roll back the application and restore data if needed. Record any known issues so the people supporting the release know what to expect.