Ask HN: What are some of the most advanced conversational UIs you've seen?

I'm a big fan of chatbots and the rise of virtual assistants. One UX pattern I've recently seen marries conversational chat UX with fluid dynamic visual elements on a web page. One example is https://www.heek.com/ , which has a chat bot that helps you build a webpage.

Are there any other great examples like this out in the wild? What is this UX pattern called?

What types of user experiences become possible when we augment a conversational agent and build some context awareness into the application or bot?