[zoogeny]

I don't think "correct" is the right word since these were open ended systems design type questions. There are many ways to accomplish the same task.

I also spent about 20 minutes on this which is why I mentioned this is a first impression. I'll leave it to researchers to develop a "relevancy" metric and objectively apply it.

In my experience, the sources were sufficiently relevant based on its responses. They were about as relevant as equivalent Google queries. Some tiny, tiny niggles, like I was explicit I wanted it to recommend approaches in Go and for one reference I recall related to distributed locking mechanisms it provided a reference to an implementation in Java. However, that is completely fine for me since the context was more about the locking on the database side and not really the implementation in a specific language.

[foobarbecue]

And the sources actually existed? i.e. there weren't any made-up ones?

[zoogeny]

The sources are urls to the cited page (e.g. stackoverflow.com, pkg.go.dev). In the side-bar next to the answer is a more standard search-result style link list with pulled quotes from the pages (like a Google search).

I didn't click every single link (as I mentioned, the citations are copious) but the few I did follow went to relevant articles. I just went back and randomly clicked several more and they all went to pages that exist and mostly relate to the content of the answer. The inline citations seem a bit more on-topic compared to the side bar which does seem more like the links were lifted directly from a search engine.

To be fair there are some lower-quality blog-spammy kinda stuff - more or less the same kind of thing you would get out of Google. But compared to GPT-4, which provides no sources whatsoever, it is an advantage IMO.