I'm a Drupal Architect and developer. I've been a software developer since all mice had fur, "front-end" and "back-end" primarily related to horses, and blue tooth was something you got from eating raspberry Italian ice. There's a line in the ether between undiscovered wisdom and uncorrected folly. Feel free to have a poke around and note you might find either.
Boiling down the zillion hours of D7 development into a short list of important changes isn't practical, so consider this a starting point rather than a comprehensive list.
In a Drupal view, one of the presentation options for a selected field is to have the field be a link to its node. What if you need the label to also be a link?
So the Content menu page (admin/content) on a stable production site loaded, and the only menu item listed was Comments...yet, the admin menu in the left nav listed all the usual suspects. WHAT was this?!
If you convert a Drupal site to a multi-site configuration, you will very likely notice a disturbing side-effect: your images no longer appear!
I had the need to add an image tag to page output that was generated inside a custom Drupal module.
If you are a Drupal developer of any level and you are waiting to explore Attachment Views, then this book is for you.
I created a view the other day, and so began the head scratching.