Ask HN: How to speed up NPM installs?

I work at a company in a backend role, but our front-end team routinely requires NPM clean / installs which take more than 10 minutes each. We're looking for a solution.

It seems the reason they clean out all of their packages, is because one dependency is another internal project and that for some reason it gets cached unless an NPM clean is run (?).

Is this truly the state of affairs in NPM? Surely there is a way to update repositories without deleting every dependency every time.