The document discusses how data-driven DNS can be used for traffic management of distributed applications. DNS lookups provide opportunities for traffic management decisions because they occur at the application entry point, can use real-time state data, happen frequently, and have low latency. A data-driven approach involves gathering metrics from applications and monitoring, then ingesting and processing the data before making routing decisions that optimize for factors like response time, load, and cost. This allows implementing patterns like geo-routing, failover, and load shedding based on static configurations and dynamic, real-time data sources.