API monitoring is the process of continuously tracking the performance, availability, and functionality of APIs to identify issues before they impact end users. Effective API monitoring provides insights into how APIs are performing, ensures they are available when needed, and confirms that they are functioning as intended. By monitoring APIs, developers can preemptively address potential issues, maintain a robust user experience, and adhere to strict service level agreements (SLAs). Key metrics for API monitoring include response time, error rate, throughput, and uptime, which provide valuable information on API performance and help identify areas that need improvement. To set up API monitoring, developers must define key metrics, configure monitoring tools, set up alerts, and ensure comprehensive coverage of all API endpoints. Advanced techniques in API monitoring include implementing machine learning for predictive analysis, utilizing distributed tracing for detailed performance insights, and automated testing and CI/CD integration. By leveraging these advanced techniques, developers can take their API monitoring to the next level and deliver an exceptional user experience.