You should end to end test. If it’s slow, do it less often. If it’s costly, again do it less often. But this is your last line of defense against bugs.
Now, every service should also unit test, with mocks of all the other services that they call. I assume this is what you mean by pact testing. These should be locally runnable, offline, as the mocks are cheap offline things. If you need data from a database, I’d recommend mocking the data too.