Ah, the perfect visual metaphor for legacy code in its natural habitat. A stack of books with "THESE BOOKS ARE HERE FOR AN ESSENTIAL STRUCTURAL PURPOSE. THEY ARE NOT FOR SALE." written on their spines. This is basically every codebase older than 5 years. Nobody understands how it works. Nobody dares to touch it. But remove one line and the entire production environment collapses like a Jenga tower during an earthquake. The irony is delicious - those books aren't valuable for their content but merely for their physical presence... just like that 2000-line function written by a developer who left the company in 2011. It's not elegant, it's not documented, but by god, it's holding up the entire billing system!