Worked on the DataDog/dd-sdk-ios repository to refactor and consolidate tracing metrics within the iOS SDK. Focused on relocating the _dd.agent_psr metric from the root of spans into the metrics map, updating the encoding logic and associated tests to align with this new structure. This change streamlined the SpanMatcher component by removing non-allowed root-level _dd handling, simplifying the metrics ingestion path and reducing potential edge-case failures. The work was implemented using Swift and leveraged expertise in mobile development and the Datadog SDK. Documentation and changelogs were updated to reflect these improvements, enhancing trace data reliability across releases.