Monitoring a system from the outside, the way a user sees it, without internal instrumentation, complementary to white-box monitoring.
Black-box monitoring observes a system from the outside, hitting the public endpoint and recording what came back, without any visibility into the internal state. Synthetic monitoring is the canonical black-box technique. White-box monitoring, by contrast, reads internal metrics, logs, and traces from inside the service. Mature observability combines both: white-box tells you why, black-box tells you whether the user actually saw it.
White-box-only monitoring can show every internal metric green while users still see errors, because the dashboards measure what the team thought to instrument, not what the user actually experiences. Black-box monitoring is the customer-truth check: if synthetic checks fail, the user-visible service is broken, regardless of what the internal dashboards say.
See the part of the platform that handles black-box monitoring in production.