I've not done it, but have you considered using `pnpm` and volume-mounting a shared persistent `pnpm-store` into the containers? It seems like you'd get near-instant npm installs that way.

The only time npm install was on the critical path was hotfixes. It’s definitely worth considering. But I was already deep into doing people giant favors that they didn’t even notice, so I was juggling many other goals. I think the only thank you I got was from the UI lead, who had some soda straw internet connection and this and another thing I did saved him a bunch of hard to recover timeouts.

In this approach the size of deployment bundles / images is not necessarily reduced.

Reduced is the size of javascript loaded into the end user's browser.