synthetic check
An automated, scripted interaction with a service that simulates real user behaviour and runs on a schedule.
A synthetic check is an automated, scripted interaction with a service that runs on a schedule and reports success or failure. The simplest synthetic check is an HTTP GET against a URL that asserts a 200 response and a maximum latency. More complex synthetic checks drive a headless browser through a login flow, a checkout, or a full user journey.
Synthetic monitoring is the practice of running synthetic checks continuously and treating their results as a first-class signal in your reliability practice. Unlike real-user monitoring (RUM), synthetic monitoring works before any real users hit a broken page: a 4am check failure can wake a human up before the morning surge.