Developed a scalable Pre-Login telemetry capability for the webex/webex-js-sdk repository, focusing on tracking user events before authentication. The work centered on designing the PreLoginMetrics interface, which enables the submission and batching of pre-login events for efficient processing. Updates to the metrics API introduced support for additional metadata and batch handling, allowing for richer and more scalable telemetry collection. The implementation maintained API stability and code quality while expanding the system’s metrics tracking capabilities. This feature was built using TypeScript and full stack development skills, with an emphasis on robust API development and effective metrics tracking for enhanced observability.