Actually, LaTeX has to recompile everything even after a tiny change (there are rare exceptions like TikZ, which can cache pictures, but even then it can put th

Actually, LaTeX has to recompile everything even after a tiny change (there are rare exceptions like TikZ, which can cache pictures, but even then it can put them into some file on its own AFAIR, so that I can still have one big file). Now that I think about it, LaTeX is a very bad analogy anyway, since LaTeX documents usually have a very linear structure.