I've tried putting these ideas into practice in a couple of previous jobs doing web development. Some applications I've written & worked on use React along with

I've tried putting these ideas into practice in a couple of previous jobs doing web development. Some applications I've written & worked on use React along with Redux for state management. For a different application that didn't use React, I used a pub-sub model to communicate state changes. Both of these work really well for certain kinds of data, and both of them also fell apart for me when things got complicated. I haven't thought hard enough about the problems I ran into to be able to categorize them in any concrete or helpful way. But, I do think that the breakdown is related to having to communicate state between components and across the system. Sometimes state changes have a necessary dependency on ordering things which can get tricky if one side is trying hard to avoid state. Sometimes wiring up state changes to the components that need it just adds communication complexity. The other thing that seems to happen when you put state on the outside is that your data schema evolves toward your code structure. In some ways, you end up duplicating the hierarchy. This has caused me trouble when refactoring. Once you realize some sizeable portion of code needs to be rewritten, but you can't change the data schema to match the new code because the data is production live, all the cleanness of the design starts to break down.