Infinite scrolling for a collection that may change its order

I am trying to implement infinite scrolling for documents stored in a MongoDB collection. Every document is a restaurant that has a numeric field rating, so I am using the rating field for sorting and showing restaurants with the highest rating first.

The problem is that the collection of the restaurants is not static. The ratings of the restaurants change in real time, therefore the order of the restaurants in the collection changes constantly. As a result, although I formally have the sorting key, it does not make much sense.

I am thinking of 2 solutions of the problem:

1. Accept that the order of the restaurants may change slightly while someone is doing the infinite scrolling. Make the front end responsible for getting rid of possible duplicates. Accept that some of the restaurants may not appear during a scrolling at all. But that looks more like working around the problem instead of solving it.
2. Only perform infinite scrolling against a static copy of the collection of restaurants. Update the static copy periodically (e.g., once a day) with the rating updates. But this approach seems overengineered. Also, what happens with the infinite scrolling at the moment when the static copy of the restaurants gets updated with the new ratings? Such scrolling will be broken as well because the problem with the changing order is still here, the order just does not change that frequently.

I am sure I am far not the first one who have faced this problem. After all, there are a lot of examples of infinite scrolling implementations out there, like Facebook or Instagram feeds. At the same time, all the articles I have read so far seem too superficial and covering only cases with infinite scrolling through static collections.

What is the right approach to deal with infinite scrolling for a collection that may change its order any time?

Thank you.

Infinite scrolling, as commonly implemented, isn't a precision navigation method to begin with. Who are your users?

• Power users are likely to hate it (I do on github, facebook, etc.) hence won't be using it too much.
• Non-power users won't be able to tell that data is missing. If they happen to be looking for a particular restaurant and it vanishes, telling them to reload the page will be a sufficient explanation for most.
• Users who scrape your data will do it without delays between requests to get all of your data.

When you show the same restaurant twice people will notice so check for those cases in the frontend.

You may also consider having a high-precision rating field for sorting. For example, if normally your UI shows integer rating, keep the floating-point rating used during the calculation and sort by that. This will produce a more stable sort.