I think this applies beyond ruby&#x2F;rails<p>I&#x27;ve seen the extremes of 100% tdd and 0 tests, and the most efficient projects&#x2F;applications are the ones that are somewhere in the middle, you don&#x27;t need tests for every single thing in your application and it becomes harmful to include them at a certain point.<p>My Personal preference is to focus on testing &quot;critical&quot; things like business logic, utilities,etc. Then have just a few end to end tests that skate the most important flows.  In the end you have fairly tested application and you haven&#x27;t wasted time asserting trivial pieces.