I think 20000 lines of code is the tipping point where code bases go from applications/libraries to frameworks. The difference is that the objects of an applic

I think 20000 lines of code is the tipping point where code bases go from applications/libraries to frameworks. The difference is that the objects of an application/library are expressed in the raw language, while in a framework they are expressed in the framework's meta-language. E.g. one might start out writing a machine learning library where a transformation of data is simply a function. But in scikitlearn, transformations of data are objects that implement a transform method. This, together with the implicit/explicit constraints on the semantics of the transform method, help create uniformity so that understanding of the codebase scales better than understanding an arbitrary collection of functions.