I've got a Node app that I'm deploying to Heroku. Their docs say it's best practice to [check in your `node_modules` directory](https://devcenter.heroku.com/articles/nodejs#declare-dependencies-with-npm) (i.e. **don't** gitignore it), for faster deploys and for dev/prod parity.

In my `package.json`, I've got loads of `devDependencies` (mostly Grunt plugins and all their deps) and a few regular production `dependencies` like Express. Heroku only needs the production deps. I'd rather not check in all my dev deps, because they come to about 50MB.

Is there some way to have a separate folder for you dev deps, e.g. `node_modules_dev`? If this was possible, then I could just add `node_modules_dev` to my `.gitignore`, and check in the regular production `node_modules` directory as per Heroku's advice.

Is there any way to do this? Or can you think of another way to do what I'm trying to do?