A hermetic test is a test that is completely self-sufficient. It is fully independent, therefore every time a test is run, you are absolutely sure that a failure is a real failure, and has nothing to do with a dependency going wrong.In order to use hermetic testing to achieve what we want, we first split our e2e into meaningful chunks. The most common breakdown is to split it into frontend and backend systems.We then run our tests within the context of the front end and back end independently. We then add additional levels of tests to make sure we make up for skipping the e2e tests like contract tests, API tests, visual tests and improving existing unit testing coverage.