Something with a 1..N and an N..M relation in it. I'll do a simple link boomarking where I can put links in a collection (1..N) but links also have many tags and many tags can be assigned to a link (N..M). After that you know a lot of things: How do I deal with relations in the framework How do I deal with nested resources Hope that helps.

I plan for 4 hours a day. The rest piles up.

In case you're using React without state management: https://github.com/vacuumlabs/react-custom-validation In case you're using Redux I suggest: https://github.com/erikras/redux-form

I think that for the React integration you should provide something like the connect decorator of react-redux to avoid the forceUpdate.