Deep understanding of the Linux I/O path and hands-on experience in at least two relevant areas: NVMe, HDD, Sata SSD, AHCI, HBA, RAID, block layer, file systems, device drivers, memory management, caching, or I/O scheduling. Diagnose failures or exceptions across devices, PCIe, firmware, kernel, memory, networking, runtimes, and applications; drive root-cause analysis through verified resolution.