2018 is the fastest year ever. More and more information and too little time to read books. We need:
Why books are dead and posts are outliers? Read in Don't read books and Cluster: More Interactive than a Book, Deeper than a Post.
Don't forget to tick it, so you know what posts you've finished.
Do you want to write CLI Apps in PHP like a boss but you never did that before? Or do you look for tips to improve your CLI project? This will help you write better and cleaner code no matter level you're on.
Mastering open-source is tough, because the topic is so wide and various. It's often long journey of blind paths and self-experience. Take this shortcut and gain years of experience in days.
Collector is the one pattern that will help your code exponentially. It's super easy to start using in every level of application. Stop learning 5 SOLID principles theory and start using it in your code today.