Datadog's JavaScript logging library helps detect and debug user-facing issues by enabling the monitoring of JavaScript console logs alongside backend logs, metrics, and distributed request traces from infrastructure and applications. This allows for real-time tracking of client-side errors and events to ensure timely issue resolution and maintain a positive user experience. By analyzing frontend error logs, users can identify patterns and trends, such as which browsers or regions are most affected by issues, and take corrective action to address these problems. Additionally, the library enables logging of custom user events, providing richer context around JavaScript console logs and enabling businesses to track key activities and improve their services. With this feature, developers can gain full-stack visibility across frontend and backend issues, allowing for continuous improvement of availability and performance.