One simulated state, run in a loop that never stops checking itself.

A per-structure model of every US home: footprint, construction, terrain, exposure. Every snapshot carries a vintage stamp.

Physics solvers roll a scenario through that state: fire spread, water, wind fields, ground motion, debris runout.

Where a hazard reaches a structure, each assembly gets a failure probability with its mechanism and onset hour.

A learned surrogate reproduces the solver's output fast enough to score whole books against many scenarios.

Recorded outcomes flow back in, and every candidate model re-runs the full back-test board. A version that loses on any leg can't ship.