Any given callee is going to deal with a bunch of both inputs and results. And it’s not clear to me what those terms mean — e.g. is the response from the databa

Any given callee is going to deal with a bunch of both inputs and results. And it’s not clear to me what those terms mean — e.g. is the response from the database an “input” or a “result”? I think your point of view would make more sense looking at the call stack — database access happens deeper than the code that handles the response, so you can’t push it “up” from there. And I mean, sure? But I don’t think that’s an inherently better frame than the one in which external sources are “upward” and your own application code is “downward”.