If you manage multiple themes with similar npm dependencies you should install npm packages globally and link them in your theme directories. First of all this saves a lot of disk space. But it also disburdens the upgrade process of development frameworks and toolkits that are used across projects.
1. Install packages globally by adding the “-g” flag:
$ npm install -g package_1 package_2 package_3 package_4 etc.
2. Link the packages in your local theme directory/directories:
$ npm link bootstrap @popperjs/core browser-sync gulp gulp-sass gulp-sourcemaps gulp-postcss postcss sass autoprefixer cssnano webpack webpack-stream
$ npm link material-components-web @babel/core @babel/preset-env babel-loader autoprefixer css-loader sass sass-loader extract-loader file-loader postcss-loader path webpack webpack-cli webpack-dev-server
$ npm link autoprefixer css-loader sass sass-loader extract-loader file-loader postcss-loader path webpack webpack-cli webpack-dev-server