Instrumenting Your Node/Express Application` discusses the importance of instrumenting a Node.js/Express application to collect metrics, enabling smarter decision-making for its progress and efficient issue handling. The process involves installing the `appmetrics` library, initializing it in the server file, and collecting CPU usage metrics. Telegraf is then used to send data to InfluxDB, where it can be stored and queried. The article concludes with next steps, including exploring collected data and building a dashboard within Chronograf.