Book-Reader-Assist/library/FOCUS Architecture/book-structure.md

FOCUS: Architecture for People Who Ship Software — Structure

• Author: J.C. Ködel
• Source: source-file.pdf (737 PDF pages)
• Chapter count: 24 numbered chapters, plus an interlude after Chapter 1.
• Page numbers: PDF pages, starting at 1. The source has bookmarks for the sections listed below.

Reading order	Section	Starts on PDF page
Chapter 1	About the Author	13
Interlude-Map-of-the-trilogy	Map of the trilogy	21
Chapter 2	The Day One Line Change Broke Three Screens	24
Chapter 3	AI Writes Fast. So What?	42
Chapter 4	Simplicity Is a Decision: KISS and YAGNI	57
Chapter 5	DRY Isn’t About Code	81
Chapter 6	SOLID Without Dogma	99
Chapter 7	Pure Functions and Immutability	127
Chapter 8	Errors Are Values	158
Chapter 9	Explicit Dependencies: DI and the Composition Root	188
Chapter 10	FOCUS in One Page	212
Chapter 11	Features, Not Layers	256
Chapter 12	The View: Dumb by Design	290
Chapter 13	The Orchestrator: Event In, State Out	331
Chapter 14	Use Cases: Where the Rules Live	386
Chapter 15	Repositories: The Exception Boundary	421
Chapter 16	Commands and Queries: CQS Without Ceremony	472
Chapter 17	Test Each Piece the Way It Asks to Be Tested	498
Chapter 18	What to Do When the Language Doesn’t Help	540
Chapter 19	Anti-Patterns: How to Wreck FOCUS	583
Chapter 20	Migrate Legacy Code Without Stopping the Factory	616
Chapter 21	FOCUS + AI: The Duo That Scales	640
Chapter 22	Architecture for humans and for models	677
Chapter 23	Build Rosie’s App	680
Chapter 24	Ship Increments Without Chaos	730

Chapter 1 occupies PDF pages 13–20. The interlude occupies pages 21–23; Chapter 2 begins on page 24. The PDF's generated contents display some chapter numbers incorrectly, so this index uses the sequence confirmed by the chapter text and bookmarks.

Source Text Index

Extracted from source-file.pdf by tools/split_book.py. Read these instead of the PDF.

Folder	Section	PDF pages	Pages without extractable text
Front-Matter	Front matter	1–12	1
Chapter-01-About-the-Author	About the Author	13–20	none
Interlude-Map-of-the-trilogy	Map of the trilogy	21–23	none
Chapter-02-The-Day-One-Line-Change-Broke-Three-Screens	The Day One Line Change Broke Three Screens	24–41	none
Chapter-03-AI-Writes-Fast-So-What	AI Writes Fast. So What?	42–56	none
Chapter-04-Simplicity-Is-a-Decision-KISS-and-YAGNI	Simplicity Is a Decision: KISS and YAGNI	57–80	none
Chapter-05-DRY-Isnt-About-Code	DRY Isn’t About Code	81–98	none
Chapter-06-SOLID-Without-Dogma	SOLID Without Dogma	99–126	none
Chapter-07-Pure-Functions-and-Immutability	Pure Functions and Immutability	127–157	none
Chapter-08-Errors-Are-Values	Errors Are Values	158–187	none
Chapter-09-Explicit-Dependencies-DI-and-the-Composition-Root	Explicit Dependencies: DI and the Composition Root	188–211	none
Chapter-10-FOCUS-in-One-Page	FOCUS in One Page	212–255	none
Chapter-11-Features-Not-Layers	Features, Not Layers	256–289	none
Chapter-12-The-View-Dumb-by-Design	The View: Dumb by Design	290–330	none
Chapter-13-The-Orchestrator-Event-In-State-Out	The Orchestrator: Event In, State Out	331–385	none
Chapter-14-Use-Cases-Where-the-Rules-Live	Use Cases: Where the Rules Live	386–420	none
Chapter-15-Repositories-The-Exception-Boundary	Repositories: The Exception Boundary	421–471	none
Chapter-16-Commands-and-Queries-CQS-Without-Ceremony	Commands and Queries: CQS Without Ceremony	472–497	none
Chapter-17-Test-Each-Piece-the-Way-It-Asks-to-Be-Tested	Test Each Piece the Way It Asks to Be Tested	498–539	none
Chapter-18-What-to-Do-When-the-Language-Doesnt-Help	What to Do When the Language Doesn’t Help	540–582	none
Chapter-19-Anti-Patterns-How-to-Wreck-FOCUS	Anti-Patterns: How to Wreck FOCUS	583–615	none
Chapter-20-Migrate-Legacy-Code-Without-Stopping-the-Factory	Migrate Legacy Code Without Stopping the Factory	616–639	none
Chapter-21-FOCUS-AI-The-Duo-That-Scales	FOCUS + AI: The Duo That Scales	640–676	none
Chapter-22-Architecture-for-humans-and-for-models	Architecture for humans and for models	677–679	none
Chapter-23-Build-Rosies-App	Build Rosie’s App	680–729	none
Chapter-24-Ship-Increments-Without-Chaos	Ship Increments Without Chaos	730–737	none