Monitoring the right metrics in AppDynamics is essential for ensuring the performance, stability, and user experience of web applications. Key metrics include Business Transaction response time, which highlights how quickly critical application paths execute, and Error Rates, which indicate issues impacting functionality. Throughput helps track the number of requests handled, offering insights into load patterns and capacity. CPU and Memory Utilization provide visibility into resource usage on underlying servers, helping identify bottlenecks or capacity issues. Database response time and slow queries are also crucial, as database delays often affect application performance. Additionally, external service call latency, HTTP response codes, and End User Experience metrics give a comprehensive understanding of how both backend operations and user interactions are performing. Monitoring these metrics ensures proactive troubleshooting and consistent performance.