root cause

You can't read the model's weights, so you debug the inputs you control. There's a four-bucket triage, prompt, context, model, or spec, that localizes the fault fast, and the real deliverable is feeding each diagnosis back so the same failure can't recur.

A model that's too good is a bug, not a win. The screen is whether your instinct on a suspiciously high number is to celebrate or to get suspicious, and whether you disclosed the leak instead of quietly fixing it.

The deployment worked. The software runs, the data flows, the demo landed. Nobody is using it. Two of the three research sets we vetted surfaced this from different angles, and it is the failure mode that ends renewals.