I've found 2 reasons that e2e tests are flakey (whether it be selenium, puppeteer or cypress): 1. poorly developed tests. There are nuances that go into writin

I've found 2 reasons that e2e tests are flakey (whether it be selenium, puppeteer or cypress): 1. poorly developed tests. There are nuances that go into writing browser interaction tests that the less-experienced will have to work through. 2. There's a weird functionality implemented in such a way that makes testing difficult. This could be something like a modal that has a fly-in animation and if you try to click it while it's animated it won't fire the onClick action. If you want e2e tests to be successful, you have to write testable front end code, which is pretty dang hard for a lot of reasons.