Great job guys, found these articles very helpful in understanding the design concepts. Difficult to find such good articles these days. Keep up the good work.

Left side menu under Refactoring needs Code Smells and Refactorings to be grouped under Catalog

Using constructor in clone method

Swift example would be great

Can u write this book in Indonesian(Bahasa) language

really a great piece of work

Proxy Pattern - In Pseudocode section, the id parameter is not passed to YoutubeManager's rendedVideoPage method

В патерні "Легковаговик" є невелика синкаксичкна помилка

Typo on homepage

Blog post on what I learned