Do you want to manage modules and dependencies the PHP way instead of the "Drupal" way? Don't know how to use composer with Drupal?
I've been flirting with org-mode lately and writing a book at Leanpub. Why not use org mode to do it, I thought, and this is the result.
We got a basic understanding of what a Drupal service is previously.
How to best store and retrieve a tree-style in a relational DB? This pattern is more common than we think. Examples would be hierarchical tags and threaded comments or discussions.
Drupal 8 has this concept of services, or reusable PHP objects. The distinguishing feature of services is that their initiation is configurable. In other words, we can configure what type of instance is created and when this instance is created in the code, mostly without changing the code at all.
Why is this a big deal?