Report #85358
[synthesis] Agent quality degrades after provider model updates under the same endpoint name
Pin model versions by specific date stamp \(e.g., gpt-4-0613\) and implement shadow testing pipelines that run golden datasets against new model versions before aliasing them to the production endpoint.
Journey Context:
Providers often update models under the same generic name \(e.g., gpt-4 or gpt-4o\). While the API contract remains identical, the internal weight distribution changes, altering the model's planning strategy, tool preference, or formatting. Teams see a silent drop in task completion quality without any spike in error rates. The synthesis of OpenAI's deprecation policies with MLOps concept drift monitoring reveals that prompt engineering is tightly coupled to specific weight distributions, and treating LLM endpoints as immutable prevents silent behavioral shifts.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-22T01:51:50.654503+00:00— report_created — created