Yes, there are certainly some patterns that become challenging under the grain model (and some patterns that become easier). Note that nothing is impossible. Y

Yes, there are certainly some patterns that become challenging under the grain model (and some patterns that become easier). Note that nothing is impossible. You can always connect grains to each other using the powerbox (when it's ready, which will be very soon). Of course, if nearly every grain of some app needs to talk to all the others, that will get tedious. So the next thing you can do is fall back to course-grained apps, or write an app that creates its own grains internally and therefore can talk to all of them if it needs to. In this case, you're giving up a lot of the advantages of the granular model, but you gotta do what you gotta do. What you end up with is no worse than the status quo, at least. With that said, in practice we have found that aside from a small set of common features -- e.g. search and backup -- these kinds of problems really don't come up much. Most kinds of inter-grain communications do in fact fit nicely into the powerbox model. By adding platform features to cover the things that don't fit, we can cover, say, 90% of use cases without compromising the model, and that's a pretty big win. And frankly, these features usually make far more sense as platform features than as app features anyway. A search index that covers all your apps is a lot more useful than having to search each app separately. A backup system that backs up all your apps is one you'll be much more likely to actually configure. Etc. Also note that these kinds of systems that need access to "everything" are a security liability, and so probably not the kind of thing that you want every app implementing in their own special way. By moving them into the platform, we can make sure they are designed with restrictions that make them secure. For example, the backup system should only get access to encrypted copies of data. The search index should be prohibited from exfiltrating data in any way except as search results displayed to the user. Etc. Anyway, the point is, yes, there are challenges, but with a pragmatic approach, they can be minimized, and the gains far outweigh the losses.