With Gitea/Forgejo you can run a local actions executor, which builds the images, pushes to gitea’s image registry, and using a script pulls them on the other side and restarts them. Worked fine in our small startup.

Concepts like Reactive programming are widely used in web/UI contexts. The problem of connecting a UI to an underlying data set is not trivial. Several frameworks deal with this.

As was already said, concerns like Accessibility are studied academically. They have more to do with user experience than the technology, so not sure if they match your question.