On the contrary. A simple data proxy involves not much computation, but mostly reshaping; what kind of thing you have becomes more important than what thing you

On the contrary. A simple data proxy involves not much computation, but mostly reshaping; what kind of thing you have becomes more important than what thing you have, and eliminating confusion in the former realm is precisely what static-typed code with proper modelling, excels at. And any competent static-typed language will have enough macro-like capabilities to generate the model code (along with as much of the boilerplate as possible) from a JSON Schema or similar. (Confusion in the latter realm, on the other hand, is one of the most common sources of remaining bugs once typing errors and other footguns are eliminated-with-prejudice.)