Logic is pretty much how you thought - with the difference, that the serialization is not utilised, but each node has their own function, and makes a Worker QRunnable, runs it in the parents threadpool, resutl signal is connected to an onWorkerFinished function which takes care of gui outputs and runs the next child if any.

Now, what I'm also working on, is that I want to separate the execution from the frontend with a light FastApi server, also allowing processes to be ran on a server.

Same page on execution, so far I kept it as a separate input/output type, which only does execution, data is evaluated from the node if it is already present, and the execution flow is completely up to the user, no guidance in that (i.e. a graph with missing values in the beginning won't solve itself when evaluating a node in the end, but it, as you mentioned, allows loops, and data storage).

An other great repo I highly suggest to take a look at is NodeGraphQt. I took the inspiration for the backround node from that, and it works really great. It also has logic to handle group nodes, which are subgraphs practically, and that would also make life a lot easier.

It would be nice to find the defacto middleground, so we can provide a nice Qt node gui similar to chainner, but make it a lot more modular. (Optional if data and params are on the nodes or on a separate / docked widget, etc).

I'd love to hear your thoughts. Do you use discord maybe?