(1) Randomise your test inputs. If you think that will lead to flaky tests, then you already have flaky code. (2) Be able to run the software locally in some

(1) Randomise your test inputs. If you think that will lead to flaky tests, then you already have flaky code. (2) Be able to run the software locally in some meaningful way, (as opposed to only seeing the software in action in prod.) My most productive code/test/debug cycle always involves main(). I spend less time imagining what the software will do, and more time seeing what the software actually does.