Traditional end-to-end pre-deploy testing systems rely on visual regression testing to catch discrepancies in interface changes between code deployments, but third-party dependencies and render-time changes can lead to unexpected regressions. Checkly's synthetic monitoring can help identify such issues by continuously monitoring a site or service for changes. Playwright, an open-source end-to-end testing framework supported by Microsoft, is used with Checkly to create synthetic service monitors that execute visual regression tests at regular intervals, alerting developers to potential interface problems before they become visible to users.