This essay introduces the Law of Viability as a fundamental principle to govern software engineering in the era of AI-generated code abundance. The author argues that value does not emerge from the volume of execution, but from the precision of Intention and the sustainability of Design. Core Contributions: IDO Paradigm (Intention, Design, and Orchestration): A taxonomy to guide human labor when code production becomes a commodity. Software Effectiveness Formula ($E_{s}=I\times(D+O)$): A model that makes explicit the shift of the bottleneck from code writing to decision-making. Technical Leadership Matrix ($2\times2$): A diagnostic tool to organize the tension between time-to-market and technical quality, defining the Convergence Point. Viability Engineering: A framework organized into 4 Pillars (Clarity, Intentionality, Integrity, and Adaptability) to ensure systemic integrity. This work serves as a practical framework for technical leadership (Tech Leads, CTOs, Staff Engineers) and as a foundation for subsequent academic research at CESAR School.