Datadog APM is a comprehensive application performance monitoring tool that has added new features like App Analytics, Watchdog, and the Service Map to enhance visibility and performance optimization. It supports multiple programming languages, including Java, Python, Ruby, Go, and Node.js, with upcoming support for .NET and PHP. App Analytics allows users to search and analyze APM data using custom tags, while Watchdog automatically detects anomalies using machine learning algorithms. The Service Map visualizes microservices and their dependencies, aiding in root cause analysis. Datadog APM integrates seamlessly with the three pillars of observability—traces, metrics, and logs—offering end-to-end request tracing and allowing for the creation of customized alerts and dashboards. Companies like Airbnb, Square, and Zendesk utilize these features to monitor application performance effectively.