One Topic. One Page. One Picture.
Mark's books have rules. One topic per page. Code on the left, visual on the right. No walls of text. No chapters that assume readers already know what they're trying to learn. Written in simple English, deliberately, because many of his readers are not native English speakers.
The production workflow is unconventional. He writes in Apple Pages - not LaTeX, not a traditional publishing tool. He keeps a research Xcode project running in parallel, adding examples as they occur to him, logging questions in Apple Reminders organized by book category. When a section is ready, he takes code screenshots directly from Xcode with full syntax highlighting, then annotates them with visual connectors and diagrams.
He has submitted multiple feedback requests to Apple about annotation behavior in ePub formats. This is what "caring about your craft" looks like in practice - fighting the small battles that make the reading experience better, even when the adversary is Apple's own PDF pipeline.
The SwiftUI Mastery series now spans more than ten volumes: views, animations, SwiftData, Core Data, Combine, Charts, and most recently AI integration using Apple's FoundationModels framework. He soft-launched the Charts Mastery book from a coffee shop in Mexico City. The AI Mastery book includes bonus Xcode projects and what might be the most self-aware parenthetical in tech publishing: "AI can be dumb. I'm adding AI prompts to help you better get what you need."