Joyce Jinhttps://joycejin.com/en/Joyce Jin's personal site. AI hardware, wearable health data, multimodal memory benchmarks, and doing the unit economics of AI products. Every number comes from my own devices and experiments.enWhat this site is abouthttps://joycejin.com/en/posts/hello/https://joycejin.com/en/posts/hello/Wed, 02 Sep 2026 00:00:00 +0800Opening note. AI hardware, wearable health data, multimodal memory benchmarks, and unit economics. Every number comes from my own devices and experiments.This is one person's site, about the things I build and use.

Why start writing now.

AI has pushed the cost of building things close to zero. Every category will soon have dozens of products with nearly identical features. The ones that survive won't be the ones with the most features. They'll be the ones people trust. Trust can't be rushed. It's built one post at a time.

Four topics.

  • AI hardware I bought myself, and the honest verdict after wearing it and taking it apart.
  • Wearable health data, from five devices worn at once. Which numbers can you trust.
  • Multimodal memory benchmarks, using hundreds of hours of my own real recordings to write exams for AI.
  • Unit economics. An AI product has to do the math on day one.

One rule.

Every number comes from my own devices and experiments. If I'm not sure, I cut it, no explanation.

One post a week. Subscribe via RSS.

]]>