I've been using a reactive websockets over HTML in Kotlin implementation that I wrote myself, and it's been the least unpleasant web development experience I've

I've been using a reactive websockets over HTML in Kotlin implementation that I wrote myself, and it's been the least unpleasant web development experience I've ever had. There really is a huge advantage when you don't have to marshal/unmarshal/validate a request for a simple callback on a button, and page loads can be much faster. That said, there is more operational complexity (though given my site is relatively small, not much yet). State that lives with the server dies with the server, so deployments can take longer if client sessions live for a while.