What am I doing wrong? Is the article not as interesting as I thought it is? Is HN not my audience?
Just looking for advice for future posts.
Probably nothing.
Is the article not as interesting as I thought it is?
Didn't read the article[1], but the title sounds interesting enough.
Is HN not my audience?
I don't think it's that. As others have said, the /new page gets a LOT of traffic, and not that many people read it and upvote stuff. So there's a lot of competition for not so much attention. Given that, luck is going to play a big factor. If somebody who's particularly interested in vector embeddings happens to see your post and upvotes it, that can trigger a cascade where it gets a bunch of upvotes. If they don't, it can remain at 0 upvotes forever until it vanishes off the first page of /new, where it's (much) less likely to ever be seen.
I wouldn't worry about it. Other than to say, if your marketing strategy depends on getting stories on the HN front page all the time, or on any kind of predictable basis, you're probably barking up the wrong tree. Submit stuff that you think is interesting and just let it be. Don't try to "game the system" or you'll wind up shadow-banned (either your user account, or your domain).
Note the following blurb from the HN Guidelines[2]:
Please don't use HN primarily for promotion. It's ok to post your own stuff part of the time, but the primary use of the site should be for curiosity.
[1]: https://aimd.app/blog/2024-01-16-using-ai-to-overengineer-40...