Highlight's Node.js Integration offers a streamlined way to track backend errors and custom metrics in JavaScript applications, enhancing session replay capabilities by capturing backend errors that were previously untracked. This integration allows developers to use the consumeError method for logging custom errors and the recordMetric method for monitoring critical backend metrics like API response time and response size through customizable dashboards. Highlight supports various Node.js frameworks, including Next.js and Express.js, and provides immediate notifications for threshold breaches via platforms like Slack. Setting up the integration is straightforward and is supported by a detailed getting started guide on Highlight's documentation site.