Oliver Davies, an Acquia-certified Drupal expert, shares insights on the significance of having comprehensive and reliable automated tests before adding new features or refactoring code. In his recent post, Davies emphasizes the importance of ensuring tests are passing and covering all existing use cases to maintain confidence in the code's functionality post-changes. He advocates for enhancing tests to secure confidence before implementing modifications and offers a free 10-day email course on automated testing in Drupal.