When To Use GenAI: A Practical Decision Framework

A four-dimensional framework helps architects decide when to use GenAI versus traditional code by evaluating reasoning needs, data types, scalability requirements, and task complexity. The framework includes three operational trade-offs (time-to-market, transparency, cost) and three hybrid architecture templates where GenAI handles interpretation and generation while deterministic code manages execution, validation, and enforcement. Real-world examples from Klarna, Bank of America, and Cleveland Clinic demonstrate effective divisions of labor between GenAI's adaptive capabilities and traditional code's reliability.