Datadog Application Performance Monitoring (APM) is a tool that helps developers understand and improve application performance by tracking how services interact to serve real requests. It automatically gathers high-level performance metrics and decomposes individual request traces in detailed flame graphs to isolate issues, prioritize fixes, and optimize overall application performance. Datadog APM monitors are designed to notify users of changes in service-level indicators such as latency and error rate for each service, providing a simple way to automate monitoring of service-level performance. The monitors can be created directly from the service dashboard via the monitor status bar, and they include suggested alerts that serve as a guide to the metrics to consider alerting on. When an APM monitor is triggered, team members receive a notification with contextual information, including links back to a service overview and end-to-end traces of recent requests. The tool provides better alerting and allows developers to immediately begin investigating issues, which can lead to improved service performance.