The 'blue book' that launched Domain-Driven Design. Published 2004 (written 2003). Subtitle: 'Tackling Complexity in the Heart of Software'. Written for Java / third-normal-form / OO developers of its era. Heimeshoff finds it a hard read and recommends starting from chapter 7 or 8 rather than chapter 1, because the valuable strategic knowledge comes in the later half. Dense enough to reward re-reading every few years.