Next.js13 'app router' I used Next.js to implement a simple blog or personal portfolio site. At that time, I had no problem using the official documentation by myself. However, I started a new project with version 14, and various changes occurred in 14, and I encountered various problems when linking app router and other libraries, and I couldn't solve the problems or my questions piled up and exploded. While looking for related lectures, I found Zerocho's lecture. I was grateful that he solved my questions one by one, and explained the part about mocking using msw and the new functions of Next.js14 in an easy-to-understand way. The disappointing thing is that there is a lot of content about the CSS clone part, and since it is clone coding, there are few parts that cover the concepts in depth, which was a bit disappointing. Still, I am listening to it with interest and benefit. Thank you.