One common problem developers often face is: how best to handle dependency injection (DI)? especially (for web developers) in an age when web technologies are changing at breakneck speed.
As with many bad programming practices, avoiding dependencies is often the faster route. When deadlines matter -- and they always do -- faster often seems better, even when you know there's a better way.
That's why it's important to keep refining your DI skills. That's why Fabien Potencier made this slideshare on dependecy injection in PHP 5.3/5.4:
If you're already comfortable with the concept, you might skip to slide 54, which gives you less tutorial and more results. Otherwise, take a few minutes to click through the whole presentation and potentially save many hours months down the road.