I don't get why we are concerned about space. Space at this scale (never reached GB level) is so cheap and easy, to me at least, yet reproducibility is not.

yeah dependency fixing is the way to do it

with NPM shrinkwrap you lock down the version of the package you installed and their deps. That way you can use the same package on all envs. Helps with testing and debugging as you're removing a variable (bad deps, outdated deps, newer deps etc)

The google3 repo is probably terabytes at this point