Deep, hands-on expertise in the encoding layer specifically: Reed-Solomon and Local Reconstruction Codes, wide-stripe and geo-distributed coding schemes, and the ability to reason quantitatively about the resulting durability, availability, repair-bandwidth, and IOPS trade-offs. This means capacity per drive is growing far faster than IOPS per drive, and maintenance operations - sealing, compaction, scrubbing, repair, rebalancing, cross-region replication - consumes that increasingly scarce IOPS budget.