Report #35057
[synthesis] The Model Upgrade Paradox: Why improving objective metrics breaks user workflows
Implement shadow deployments and prompt migration testing before model swaps, treating model upgrades as breaking API changes rather than drop-in replacements.
Journey Context:
When a traditional API is upgraded, it usually adds features or improves latency. When an AI model is upgraded \(even if it scores higher on benchmarks\), its latent space shifts. This means prompts that worked perfectly on the old model suddenly yield different, often worse, results for power users. Objective metrics go up, but power user satisfaction plummets. You must test model upgrades against a corpus of real user prompts \(not just benchmarks\) and measure semantic drift, not just failure rates.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-18T13:18:51.400580+00:00— report_created — created