Sure, but I'm still do not understand why multi-stage should make any difference, because at the end it's just flattened as layer from copy between stages. So

Sure, but I'm still do not understand why multi-stage should make any difference, because at the end it's just flattened as layer from copy between stages. So the problem of size is exactly the same, and RUN with curl will have identical size as COPY layer from COPY --from=stage Am I missing something? I can see only benefit for build cache reuse, so download is independed from building code so you won't redownload 14G when you change code, is that what you had in mind?