There's physical Amazon Fresh stores in the Seattle area (at least) which has the just-walk-out technology. I tried the one in Factoria out and it was ... interesting. A lot of groceries were pre-packaged but it had most things that I was looking for.

Felt like a "scaled-up" convenience store. Not having a line was very nice.

How does just walk out work with produce?

The Amazon fresh near me has a buggy with a bunch of cameras and a scale on it. When you drop food items into it, it's automatically added and weighed. When you push the buggy to an exit line it checks for any errors then emails you a receipt.

If you're wondering how it detects the produce, produce in the US has tiny little stickers on it or at least a PLU code where its sitting. You enter that 4 digit code and it gets weighed.

Could they do something where each bin of produce is on a scale so that the system charges you for the weight no longer present rather than making you weigh the specific selection?

That would be nice. I fear the solution is individually packaged potatoes increasing plastic waste.