Efficient serverless release with image caching

My current deploy system is to push a updated docker image to docker hub (with git hash as tag) and run "new release" and pass the updates docker hub instance tag. However, it does a full download of the new image (20-30gb) instead of caching. Every small update is currently very slow to roll out. Is there a more efficient way of doing deploys? Or letting it know that a docker image has been updated-in place during dev? Thank you!