Learn from the very basics to the advanced things of Drupal 8/9. All Drupal tutorials on here are free of charge. If for some reason you'd like to see a particular Drupal 7 tutorial, please do get in touch.
Drupal 9 - Invalidate Cache Tags
Caching is a great way to get exceptional performance on Drupal sites. All sites should be cached. However, there are times where caching can serve users wrong data.
Create a Config Page - Part 4
Learn how to create a simple configuration form for your custom Drupal module
How to update Drupal 9? (Security)
By now your Drupal site should be on the latest version of Drupal 9. If it's not, and you don't know how to upgrade your site from your previous version to Drupal 9, use the contact page to get in touch and I'll see how I can best help you out.
Display output in terminal from hook_update_N.
Every now and then we find ourselves needing to make a big update to entities within our sites. We could write code and run this using our browser using the Batch API, however, if it's just a one-off, then using the hook_update_N would suffice.