Huanyu

Make something . I’m . Most people call me Harry. I’m based in , where I work on AI and build tools I want to use myself. This is my personal corner of the internet: projects, writing, , and whatever else I get curious about.

FR 00 · A reel, 2021–

Notes on engineering and the visual world.

Harry Xie · Seattle
AI · 6 min Append-Only or It Didn't Happen The four changelog entries I wrote while I was wrong are the point. An agent-improvement log has to be non-retconnable. 2026·10·01Read →
AI · 7 min The Outer Loop Is the Product An eval collapse that looked like an agent failure was an empty tenant. The asset is not the agent's configuration. It is the loop that produces it. 2026·09·24Read →
Essay · 12 min Two Weeks On Call with My Agent My part of the shift fit on a phone For two weeks in August 2026 I was on… 2026·09·21Read →
Agents · 3 min Mirror: An E-Ink Screen That Shows One Thought an Hour This is not the usual agent post I write here. There is an agent in it, but it… 2026·07·30Read →
AI agents · 18 min How Do You Know If Your Data Agent Is Any Good? A field guide to evaluating a data agent: why the answer key is software, the clock is a… 2026·07·01Read →
AI · 5 min The 0.3% Bug That Wasn't What I learned the embarrassing way about debugging a system that can be wrong and right in the… 2026·06·29Read →
AI · 7 min The Error Contract Matters More Than the Happy Path What a production data agent taught me about treating tool failures as control flow, not exceptions. 2026·06·23Read →
AI · 11 min The System Prompt Is the Last Resort What I learned from a SQL subagent that hallucinated columns five times in a row, and the two-skill system I now run on every harness change. 2026·05·20Read →
AI · 7 min What I Actually Learned Building a Data Agent This is the first post in a series about building data agents — systems that let people ask questions… 2026·05·07Read →
End of reel · About

Make something wonderful. I’m Huanyu. Most people call me Harry. I’m based in Seattle, where I work on AI and build tools I want to use myself.

hi [at] huanyu.io · GitHub · LinkedIn · RSS
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FR 00 / 00 Title card
All writing
Clip 01 · 2026·09·07
Latest Append-Only or It Didn't Happen 2026·10·01 · 6 min All writing