Mallory Mooney discusses the importance of tagging in modern dynamic environments where large-scale applications are distributed across multiple ephemeral containers or instances. She explains that tags provide context for services and infrastructure, enabling users to isolate individual services for more comprehensive analysis. The article covers best practices for tagging, including collecting metadata from infrastructure, using standard or recommended lists of tags, and assigning custom tags to services and hosts. It also highlights the benefits of integration inheritance, where Datadog automatically collects and applies tags from cloud providers, container platforms, or configuration management tools. Tags allow users to organize complex data streams, pivot between data points, and correlate application data for seamless troubleshooting and issue resolution. By applying these best practices, users can create a complete picture of their application activity, provide context to each moving piece of their stack, and be more proactive in addressing issues before they impact customers.