Unfortunately with NPM this is still awkward, because as soon as you try to shrinkwrap your project, it doesn't just pin the version numbers, it also pins the full source location. That's in direct conflict with (and apparently takes precedence over) using one of the local caching proxies that would otherwise be a useful practical solution to this problem, and the situation gets even more complicated if you have people building at multiple locations and want each to have their own proxy.

Yarn seems to have a better approach to this. It has a few problems of its own, notably surprising, quiet updates to the lock file when using the default options (IMHO a mistake since the big selling point of Yarn is its deterministic, reproducible behaviour) but at least you can do something resembling a local cache combined with something resembling version pinning, which is the ante for any sane build system.