I can't believe it was written by Google engineer... It's like promoting of approach "my module works" - when you use unit-tests only, everything can work fine but not in collaboration. How it's not obvious for that Google engineer? I'm sure it even sounds offensive for a lot of Google engineers, especially for those who work on e2e-testing tools. See how many downloads one of them have in npm:
https://www.npmjs.com/package/protractorIt's the most awful article what can be found in that blog.