Synthetic monitoring is a proactive approach that uses automated testing scripts to test websites or apps, identifying issues before they impact real users. Frontend Synthetic Monitoring involves using virtual agents to simulate user actions, ensuring production site performance regardless of user activity. It offers various types of tests, including single-URL monitors, browser clickpaths, and mobile simulation. Synthetic monitoring is distinct from Real User Monitoring (RUM), which tracks actual user interactions, providing early issue detection and long-term insights into application performance. Implementing synthetic monitoring can lead to proactive issue detection, comprehensive test coverage, improved user experience, higher operational uptime, reduced revenue loss, and streamlined troubleshooting. It is commonly used in login flow validation, e-commerce checkout process, dynamic search functionality, and third-party integration checks. Checkly is a popular tool for frontend synthetic monitoring, offering features like monitoring as code, sandbox security, automated debugging, and a CLI workflow to simplify implementation.