The value of testing Drupal - Using docker containers!
Check the all blog post here:
https://www.acquia.com/blog/value-testing-drupal
If you are a Drupal contributor, one of the things that immediately pops into your mind is the time that takes to test your patch. Testing happens throughout the whole workflow of getting a change in Drupal core and contrib modules. Testing is what keeps you awake to see if your patch failed or passed. Testing is what makes you pull out your hair or jump with joy.