https://cluj2019.drupaldays.org/prepare-your-modules-for-drupal-9
In this short talk, I will discuss the best practices on developing modules for Drupal 8 with an eye on having them compatible with Drupal 9.
For those who don't know yet, Drupal 9 is just around the corner. After a brief discussion of what will change in Drupal when that new version is released, I will show some tools can already perform a health check in your current code.
Finally, we will conclude by discussing the trends in Drupal 8 development that indicate already which type of functions will eventually be deprecated, and how that can be leveraged to minimize future workloads.
https://www.youtube.com/watch?v=22V4Kz_IYsU&ab_channel=DrupalDevDays