The question arrives eventually
Any system that affects people produces a moment where someone asks why. If the honest answer is that a model decided and nobody recorded the inputs, you have a governance problem that no amount of after-the-fact analysis solves.
Reconstruction beats interpretation
You cannot inspect a model’s reasoning, but you can record everything around the decision: the inputs, the retrieved context, the prompt version, the output, and the human action afterwards. That record answers the practical question even though the model stays opaque.
You can’t explain the model. You can explain the decision — if you wrote down what went into it.
Version everything that shapes behaviour
A decision from March is only explicable against March’s rules, prompt, and thresholds. That is why prompts belong under version control with the version stamped on each interaction.
Prefer structured decisions where it matters
A classification into one of six categories is defensible and auditable; a paragraph of free text is not. Constraining the output space is both a guardrail and an explainability feature — the most effective control there is.
Keep the human decision point visible
Where a person reviewed or overrode the system, record that too. “A model suggested, a named person approved” is a far stronger position than an unattributed automated outcome, and it is the copilot pattern doing double duty.
Decide the retention window deliberately
Explainability requires keeping records; privacy requires not keeping them forever. Set the window on purpose, in advance, alongside what the system was allowed to see in the first place.