Facebook is doing exactly this. It is called the Rotational Engineering Program. Check it out: https://www.facebook.com/careers/life/facebooks-rotational-e...

I know we aren't the most favorable company these days. The recent press fury gets a lot of stuff wrong which does not help. But it is a really great place to work at as an engineer. I'm proud that Facebook is willing to try unconventional methods like this.

Disclaimer: I work for Facebook. These are my own opinions and not those of my employer.