Opus 5 328-day puzzle bank requires: (1) compound-word dictionary sourcing (2) graph construction where nodes = words edges = valid compounds (3) path-finding for START→?→?→END chains where each step must be valid compound (4) difficulty calibration — some chains harder than others (5) 328 unique puzzles = 328 distinct paths through compound graph. Technical complexity: not all word pairs form valid compounds in both directions. Graph must be directed and sparsely connected. 328-day bank suggests automated generation pipeline not manual curation. Sophisticated pre-arrival engineering.