Worked on the corretto/corretto-21 repository to address a critical bug affecting system CPU load metrics on Unix platforms. Focused on improving the reliability of OperatingSystemMXBean.getSystemCpuLoad by introducing null-safe handling in the isCpuSetSameAsHostCpuSet method, ensuring that null values in containerMetrics and cpuSetCpus no longer cause runtime failures. Utilized Core Java and system programming skills to deliver a robust patch that prevents NullPointerExceptions, thereby enhancing the stability of OS metrics reporting. This work reduced the risk of crashes and misleading monitoring data in production environments, reflecting a careful and defensive approach to Java system-level development.