We don’t know how massive the project is, but in any case building and immediately building again of course will be fast. How fast is it if all files have a single line changed, for example refactoring a log message?
Not to mention we haven't even gotten to discussing tests.
> in any case building and immediately building again of course will be fast
FWIW, the compile time test above was done comparing consecutive commits. Which in this case happened to have ~3-4 lines changed.