Our solution was two test suites. End-to-end (which I will fight for being the highest value test site, and it's not close) had no external dependencies. And

Our solution was two test suites. End-to-end (which I will fight for being the highest value test site, and it's not close) had no external dependencies. And a separate test suite that touched external services, split into two components: one that tested our integrations, typically against a remote testbed (if the 3rd party was competent enough to have such a thing), and a second chunk that attempted to see if remote api behavior had changed. Which it does with annoying regularity.