Enterprises are investing heavily in Cursor, GitHub Copilot, ChatGPT Enterprise, internal AI platforms, and frontier models from OpenAI and Anthropic. But the harder question is still unanswered: What return are we actually getting from AI? Counting licenses, prompts, active users, or generated code measures adoption. It does not measure value. A better approach is to measure AI ROI from the leaf nodes of the organization upward , starting with the application engineer and the application they own. Start With the Application For every application, measure concrete changes over time. The key principle is simple: Every metric should have a unit. Minutes. Deployments. Incidents. CPU-hours. Connections. Engineer-hours. Dollars. Avoid vague measures such as “resiliency improved 20%” unless the denominator and method are clearly defined. The Leaf-Node Ledger Each application can maintain a simple before-and-after ledger. AI usage can then be overlaid on this data: Copilot usage, Cursor usage...