When should you clear the cache after a user deletes a message?

Cache should be cleared immediately after a user deletes a message to keep the interface and application data synchronized and prevent showing deleted content. This is especially important if the cache is used for quick message display without re-requesting from the server.

For example, if you cache a list of messages in a local database or memory, after deleting a message, you should remove it from the cache or update the cache so that the user does not see outdated data. This is usually done immediately after successful deletion confirmation on the server or locally if the deletion occurs offline.

Thus, clearing the cache after deletion helps avoid data desynchronization and improves user experience.