I agree with the writer about the statement that you don't need a 100% test coverage but you still need to check your coverage. I mean you need to run coverage and go through your code and see if there is any gap in your testing.
That said I don't agree with the statement "mostly integration" the reason is that he don't take into an account the ROI of a test, he only take into account the outcome. I mean e2e tests are the best to catch bugs but they are harder to achieve harder to debug and harder to maintain. Same go for integration test they are harder to debug, maintain and perform than unit test. Developpers forget that their time is money and that if they spend time on a test just because it make them feel safe that mean that the project will cost more money.
The general rule I use is simple. When you test, test behavior not code and do your test at the lowest level possible.
