Audience
This section explains who the book is for, which turns out to be readers who looked at Linux From Scratch and decided the main thing missing was a little more adversity.
This book is for readers who already know what Linux From Scratch is, understand why someone would do it, and somehow concluded that the concept still had room to become more opinionated. If LFS struck you as educational but just a little too polite, then yes, you are very much in the target audience.
It assumes a reader who is comfortable around shells, source builds, compiler toolchains, partitioning, boot problems, and the general principle that when the machine becomes unreasonable, you are the nearest qualified adult. You do not need to be a compiler engineer, a kernel developer, or someone who reads ABI notes for recreation. But you do need to be willing to read errors carefully, look things up, and fix your own mess with something resembling composure.
This is not meant as a first introduction to Linux. If your current strategy for unfamiliar terms is to continue confidently until the system either boots or catches fire, the book may still teach you something, but it will do so in the tone of a disappointed physics experiment.
If Linux From Scratch looked useful but insufficiently adversarial, this book may be exactly the questionable decision you were hoping to make.
The intended reader is patient, moderately stubborn, and interested in understanding why the system works rather than merely confirming that it currently does. The book is especially aimed at people who want an LLVM-centered build on purpose, who are willing to question inherited filesystem layout, and who prefer deliberate choices over historical leftovers with good branding.
In short, this is for readers who value intent, traceability, and the occasional regrettable quantity of manual labor. If that sounds appealing, welcome. If it sounds exhausting, that is also useful information, and likely the kindest diagnostic this project is going to provide.