This is a case study detailing how frontend team tried to make the best of their situation in an organization with systemic problems in how they approach design, frontend and development - as in, corporate hell with silos, where graphic designers design things completely out of touch with platform used on the backend, project manager/owner refuses to fix communication and also refuses to address legitimate issues with wrangling the code to achieve something similar to design mockups, and frontend team has to hack their way through all this without affecting anyone else in the organization.
If you work in similar environment (maybe bail out) the book may help illustrate how to smuggle in some standards and best practices into your codebase, but the tech stack is very specific and won't be much actionable help.
This book is NOT about different frontend architectures, design systems, and ways to organize work - it's just a case study. Arguably most of the problems could have been fixed if designers and developers could / were allowed to communicate. (This book treats design mockups as something saint that can't be questioned and changed - that's not healthy.) Other than that... It's nothing groundbreaking. It's just bridging the gap between old style frontend development (think 2000-2005) and new (2015+). Maybe I'm judging this too harshly - I'm fortunate enough to work in a company that supports better collaboration and effort- and time-saving tools, for everyone - but please, a lot of frontend architecture depends on things that start NOT on frontend. If design is mucked up (not even by designers' fault - there's high chance they're working on incomplete data too), if it doesn't match the backend, heck, if the project itself is not suited for the platform chosen by someone higher up... then your frontend architecture will be at best an effort to put lipstick on a pig. And/or delay the moment when developers run away screaming.
The author boxed themselves in the frontend slice of the pie, without consideration that a project is a team effort. As a case study, it's ok. But I can't recommend this to anyone, because there is not one word of warning that the situation here is very specific and NOT something desirable (maybe they couldn't say this - still, can't recommend a book that doesn't challenge communication issues and thus indirectly promotes siloing). AND it's just one specific tech stack.