Mentioning their startup’s name, right at the top, isn’t a great start for me. OP didn’t need to do that, it means nothing to me, and it doesn’t add anything other than advertising. A few other phrasing choices like “full technical details on our website” evoke a recruiter spiel a little bit, because of wrong time and place — this is a comments section, and to me the writeup is a bit too detailed and overly confident in how interested I am. If I care, I’ll ask, or I’ll go to your profile.

Sounds like OP was just excited; unfortunately, the practice of using HN to “organically” advertise startups (particularly through blog posts) is quite common nowadays, and I can’t help being sensitive to it as I feel it doesn’t help discourse. This post was relevant and interesting though; thanks for flagging it as such.

Why don't I see down arrows? There are no down arrows on stories. They appear on comments after users reach a certain karma threshold, but never on direct replies.

Also explained here:

https://github.com/minimaxir/hacker-news-undocumented/blob/m...

I just voted you up to get one more point closer!