Beyond perhaps a smoke/availability test, I don’t know why you’d perform UI testing. Too brittle, too slow, too much of a pain to maintain compared to the value.
I like UI tests as the test are so thorough. You test the entire stack from database to webserver and final page render. Say you test a sign-up form. The next test logs into a mail account to check if the welcome email has arrived, checking the job scheduler, 3th party email service and if the link in the email works as intended. I don't mind a bit of brittleness given the large test surface e2e tests cover.
how do you perform automated in your build pipeline? I am genuinely curious and looking for new ways to do things.
You do so you can go sleep knowing you are making money and nothing breaks.