Model Retraining Strategies

Retrain too slowly, and your model goes stale. A recommendation model updated once a month is outdated almost the entire time it’s serving users.

Retrain too often, and you burn compute for little gain. An ad click model retrained every hour might cost 30× more than a daily schedule, but the improvement in freshness is often small.

The real problem isn’t choosing between frequent or infrequent retraining. It’s finding the balance between freshness, cost, and risk.