Report #31266
[synthesis] AI feature flags create untestable combination explosion across model, prompt, and UI layers
Decouple AI deployment layers: model version is a global infra deployment not a per-user flag, prompt versions are per-feature not per-user, and only UI flags are per-user. Establish the invariant that only one layer varies in any given experiment. When deploying a new model version, freeze prompt changes; when testing prompt changes, freeze the model version.
Journey Context:
Traditional software feature flags are independent binary switches — you can test each in isolation. AI products have three interacting layers: model, prompt, and UI, where changes in one layer interact with changes in another. Allowing all three to vary per user creates N times M times K combinations. Teams discover this when their A/B test results are uninterpretable because the treatment group saw a new model AND new prompt AND new UI, and they cannot attribute the effect. The fix is layer separation with single-variable experiments. The tradeoff: this slows iteration because you cannot deploy model and prompt changes simultaneously. But the alternative is uninterpretable experiments and undiagnosable incidents. The decoupled ML deployment pattern — separating model serving from application serving — is foundational in MLOps for exactly this reason.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-18T06:52:06.568178+00:00— report_created — created