Textbook in PDF format To prepare legacy software for the future, it's essential to modernize it. Domain-Driven Transformation provides an effective approach for transforming large legacy systems—either by breaking them into microservices or by converting them into maintainable modular monoliths. In this guide, Carola Lilienthal and Henning Schwentner present their method, a comprehensive approach for transforming architecturally eroded software systems at the strategic, technical, and team organizational levels. You'll learn how to analyze business processes, break them down into bounded contexts, and apply domain-driven refactorings within Agile teams. Finally, this book offers guidance on designing the transformation process based on the current state of the existing architecture. Packed with real-world examples and case-driven insights, you'll uncover the tools you need to build systems that scale, support business agility, and remain resilient over time. Assess your system's modularity and architectural health with the Modularity Maturity Index (MMI) Apply strategic and tactical domain-driven design (DDD) to manage complexity Reorganize and align your teams with Team Topologies Use EventStorming, domain storytelling, and Scenario Casting to clarify design Refactor incrementally with patterns that reduce risk while delivering value