Lazarus, a command and control cluster automation system built by Twilio, automates frequent operational tasks to improve scalability and efficiency. It addresses the challenges of running thousands of microservices in a large-scale distributed system by providing automated remediation for failed hosts, services, and other issues. By analyzing events and triggering workflows, Lazarus minimizes false positives and true negatives, ensuring that only complex failures are escalated to on-call engineers. The system is designed to work with existing tools like Nagios and Datadog, and provides a flexible configuration management framework, notification engine, and auditing & reporting features. With 90% of instances in Twilio's cloud infrastructure running with Lazarus remediations enabled, the system has been successfully deployed for over two years, improving resilience and reducing engineering workload.