The results of the categories look similar to what happens when prompting ChatGPT with "describe a list of {genres/moods/etc.} for <content>". Also the links are all for query pages on amazon/spotify/etc, which says LLM to me (rather than a database). This dynamic schema generation -> UI supported query builder seems like a really interesting direction. I'd love to see it for the web more generally and I bet Exa.ai+LLM of choice would be a pretty good place to start. If it's an LLM I'm curious about hallucination rates and excited for future web-level RAG in only returning real objects.
Also you can supply content which doesn't exist and it will automatically infer genre and such (another strong indication of LLM). I.e. you can imagine the aesthetics of the kind of content you might want by title and then use the UI to explore real recs related to that.
PS to the creator: I love the simplicity of the design and the execution is inspiring. Sent a dollar for my searches :-)