Testing AI systems

How to test AI-powered systems without writing brittle assertions against exact model prose. The core move is drawing a line between deterministic orchestration (parsing, routing, permissions, state, budgets) and the small nondeterministic model boundary, then layering unit, integration, contract, and end-to-end tests so each layer verifies exactly what it can verify cheaply and reliably. For builders shipping AI features who need a test suite that survives model updates and still catches the failures that actually cause incidents.