In an era where speed and adaptability are critical to national defense, the U.S. Department of Defense (DoD) must overcome the limitations of fragmented technology adoption and legacy bureaucratic structures. Despite investing in powerful tools and methodologies from Agile and DevSecOps to Artificial Intelligence (AI) the DoD is unable to harness their full potential due to a persistent sociotechnical divide. This chapter argues that modern defense challenges cannot be solved through technical innovation alone; they require the integration of people, policy, and technology into a unified, adaptive enterprise. Through a detailed analysis of recurring failures in acquisition and integration supported by case studies, this chapter exposes how siloed processes, misaligned incentives, and risk-averse cultures continue to delay delivery, orphan innovations, and undermine mission effectiveness. It presents a holistic digital engineering framework that links modular design, continuous delivery, and AI-augmented workflows with organizational transformation, adaptive governance, and empowered human–machine teaming. By aligning sociotechnical elements across the enterprise, the DoD can move from static program execution to dynamic capability evolution delivering trusted, mission-ready systems at the speed of relevance.