Off topic, but I wanted to highlight the open source contributions that Instacart have made. Have a look at all the good stuff at https://github.com/ankane - chartkick, ahoy, pghero, searchkick, blazer and more.

Edit: should also have linked to https://www.instacart.com/opensource

Those are fairly common. Most big retailers have a test store. Some are just for in-house use, and some have real customers.

That's fancy! Thanks for sharing!