&quot;For external services (I rarely write code that doesn&#x27;t rely on at least one SOAP endpoint) is there any alternative to mocking the service and the response data?&quot;<p>In practice, no. Though I prefer some variant to dependency injection to &quot;mocking&quot;. I consider the testability a first-class concern and code accordingly. Exactly how this manifests varies suprisingly widely between various languages. You don&#x27;t mention your language, so I don&#x27;t have specifics.<p>&quot;And then should your tests also verify that the remote service works according to its contract?&quot;<p>Yes, but rather than thinking of that as &quot;automated testing&quot;, you&#x27;re better off thinking of that as &quot;service monitoring&quot; that happens to look like automated testing. Consider something like: <a href="http:&#x2F;&#x2F;n8v.enteuxis.org&#x2F;2011&#x2F;06&#x2F;integrating-nagios-with-test-driven-development&#x2F;" rel="nofollow">http:&#x2F;&#x2F;n8v.enteuxis.org&#x2F;2011&#x2F;06&#x2F;integrating-nagios-with-test...</a>