In today’s startup environment, rapid product validation is essential. Yet, for companies building complex, domain-specific technologies from scratch, conventional Agile practices can be more of a hindrance than a help. While Agile excels in iterative improvements and adaptive planning, it often falters when clear foundations and architectural vision are absent. The tension between ideation and execution, especially in engineering-heavy startups, calls for a methodology that offers both flexibility and structured guidance. Enter Arch-Agile—a planned change in software development aimed to speed up the creation of a Minimum Viable Product (MVP) while keeping the discipline needed in fields such as aerospace, med-tech, and energy.