Looks like the book explains the base/core of JavaScript and how some of the concepts work in JS under the hood.
Although it is good to have this knowledge but shouldn't i be focusing on laying the architecture of JS apps and how to scale them? Given that i have been working in the industry for 6 years now.
You are right, the book is about base/core of JavaScript and how they work under the hood. I think you already know that then you are well into the path of becoming an expert.
I recommended this book as you mentioned JavaScript Expert. I think expert involves a very deep knowledge of JavaScript itself and how it works under the hood. This is why recommended the book.
Although it is good to have this knowledge but shouldn't i be focusing on laying the architecture of JS apps and how to scale them? Given that i have been working in the industry for 6 years now.