Consult when writing or reviewing Python, or sketching types/interfaces in a design doc or any markdown (the sketch is still Python). Covers pydantic Field rules, members-not-free-functions, co-locating constants with their owner, keyword-args-when-ambiguous, typed numpy contracts vs DataFrames, TYPE_CHECKING / annotation rules, and test discipline: the taste layer on top of ruff (ALL) + ty (strict).
