Thank you for mentioning Donut! I have never heard of this app, but I have certainly heard of this concept. I think DHH or one of the other keynote speakers at RailsConf were talking about this. They built it for their company, and put all kinds of thought into the weird questions that could make a platform like this awkward, like "what if there are an odd number of people this week" and "how do you make sure that a tuple is not repeated too frequently but stay mostly random"
Do you mind sharing a little bit about your experience with Donut? I'm sure they have paid attention to these things if it's the focus of the whole company. I'm on board with the concept, I'm looking for specific feedback on I guess Donut's implementation before I try introducing this or something like it at my org.
I guess "Haven't noticed any issues" would be fine too. It seems like a pretty simple idea and hard to do wrong, but sometimes when you try things you find out...