I haven't written a book but just take TDD philosophy but apply it to e2e. For example, if you have an e2e test that often fails because something times out, or you've had to set a high timeout, then dig down why and fix it. Turns out you have a JVM that often has a 2s GC but no alarms, and yes, it impacts customers too. Fix that problem, don't get rid of the test (or all the tests). You got a slow third party thing, put an abstraction in front of it so that username: MyE2EUser's traffic goes to a shim. Then either negotiate with third party, or make interaction with third party system asychronous. Or does resubmitting the page order the product twice?! lol. I wish those were the old days. All that being said, I haven't done this for a couple of years now, and I have the joys of vastly simpler systems at vastly huger scale, so I may be seeing the past through rose tinted glasses.