This period witnessed the maturation of software development into an engineering discipline, with a growing emphasis on structured design, modularity, and system-level thinking to manage complexity. It catalyzed a shift from autonomous programming to disciplined practices, including architecture consideration, decomposition strategies, and end-to-end thinking across layers and components. Historical Significance: The era laid foundational concepts—system decomposition, complexity management, and design-to-integration methodologies—that informed subsequent tooling, processes, and research directions, establishing software engineering as a disciplined, measurable field with enduring influence on design, analysis, and maintenance practices.