I wrote two chapters of this book - Drupal 7 Module Development and I co-wrote it with
Matt Butcher,
Larry Garfield,
Matt Farina,
Ken Rickard,
and John Wilkins.
Go buy a copy!
I am the owner of the
configuration management initiative for Drupal 8.
You can follow this work at the dashboard
on groups.drupal.org. 
I used to work at NodeOne in Stockholm, Sweden. NodeOne is the largest pure Drupal consultancy in Europe. They have built websites for clients like IKEA, SFBio, and Möbler. If you need some work done get in touch!