This breaks down on bigger projects spread across multiple source files, at which point one needs some "make" tool such as ASDF for CL where one can pile macros into earlier files and then make other files with code using those macros dependent on the macro-bearing file(s). This can make for a lot of recompilation after minor changes, so I just take my chances and (yep) recompile all when in doubt (which with today's systems goes pretty fast).
