What is Prometheus Metrics?
Prometheus metrics are the time-series telemetry data emitted by scraping workers, proxy gateways, and extraction pipelines to track system health in real-time. In a scraping context, they move observability from binary "did it run?" to dimensional "what is the 95th percentile latency of our residential proxy pool targeting this specific ASN?" Without them, pipeline failures are silent and debugging is guesswork.