GoMining mined the first known Bitcoin block produced end to end on Stratum V2, using the DMND pool's Job Declaration functionality to construct and declare its own block template rather than accept one from a pool. The block carried transactions from GoBTC Pay, GoMining's open Bitcoin payments protocol, which makes this the first time the new architecture has been used to power a live product. It matters because of a structural problem: under the legacy Stratum V1 protocol, the pool operator,...