While code of this size and scope can be unclear, it is not where the real problem lies. In general, what's not clear is some version of "what does this do" and "why is this being done" where "this" is often a function call with an arbitrary amount of complexity behind it.
When the code is mostly calls to well-documented APIs, clarity is achievable (though not guaranteed.) if it is more complicated than that, I do not know that there is any way to achieve clarity other than to structure it, internally, in that style.
When the code is mostly calls to well-documented APIs, clarity is achievable (though not guaranteed.) if it is more complicated than that, I do not know that there is any way to achieve clarity other than to structure it, internally, in that style.