[basicallybones]

I use both, so here is what I'm doing and why I find value in staged Docker builds.

I am running a (relatively new) NX monorepo, which deploys ~6 microservices to various K8s environments using Skaffold. All services are Typescript, Node 20.11, with pnpm as a package manager.

I have separate build files for certain common base images, which mostly are Node-($v)-alpine with a few CI/common dependencies installed. I use Skaffold to compose the image builds.

When I Dockerize each service, I need to install dependencies for that specific service only, and in that case the install/build specification must be the same as the runtime specification. Rather than creating separate build image files and composing them with Skaffold, I simply use a build stage to install the microservice dependencies (using one of the base images with NX and PNPM), then copy them to the final image (which does not have those deps). This is a pretty common pattern, and I like working with it. The advantages to build stages are readability and simplicity (no extra orchestration needed), and the whole setup makes it very difficult to make mistakes.