Two things, and the interface is the easy one. Lesson 07 of Becoming Forward Deployed Engineer (October 22, 2026) normalises exactly a token limit and a temperature across providers and passes everything else through by native name, which is the right amount of abstraction. The part that has to survive the switch is the eval threshold per surface, kept in a routing row with the model, the fallback, the threshold, and the date it was last run. A candidate runs the surface's sliced eval before it enters the fallback list, and the threshold runs again the night the fallback fires. The quarterly review of my own table finds about one surface a quarter routed to the flagship for no reason other than that it shipped that way, and a pricing agent of mine with no such check drifted 14% under benchmark in five weeks.
Two settings travel in the interface. The eval threshold per surface is what has to survive the switch.
The insurer case, the two-settings tuple, the routing row with its fourth column, and the two runs a fallback owes you are in One Interface, Several Providers Is the Easy Half. The Eval Threshold Travels. The three points, the 13.7, and the 2x come from Which Model Is the Smallest Knob in the Architecture Review. The 14% drift from a loop with no check is in The Stop Rule.
Last reviewed 2026-10-23 · 1 min read