title: Why should I write unit tests if I already have E2E tests
body: <p>If we're already doing <a href="https://www.techopedia.com/definition/7035/end-to-end-test" rel="noreferrer">E2E (end-to-end)</a> testing do we also need to write unit tests? </p>
  
  <p>Considering we are doing all functional testing in end-to-end testing, what are the pros and cons of doing both?</p>