cascade

The cheapest correct answer beats the best answer at scale, so routing is a cost problem with a quality floor. The three routing signals that work, the cascade that trades latency for cost, and the measurement that catches quality loss no latency dashboard shows.

The signature is unusual: many jobs degrade together, throughput collapses, and the drop counters stay at zero. Reading pause counters backward along the paths to find the origin, the three conditions that produce one, and the configuration change that stops it happening again.