For Sarah Fan · Lemma (YC F25) · SF Tech Week 6–10 Oct

Yo Sarah — I love people, and I already bought my ticket.

These are the rooms I've co-run and how many people came. I make content on Instagram and LinkedIn, videos and numbers are below. I also work in AI. I build agent observability on top of our own product at Deck, so Lemma is the thing I'd want everyone in that room using. Would love to come to SF and work with you.

Sunwoong Ha · Montréal · sunwoongha1@gmail.com

Reach

Top post, 1 day before yours: “I bought a one way ticket to SF.” — 4,353 impressions, 50 reactions, 13 comments.

The videos — all me, on camera

A friend shot it — I cut, captioned and posted every one · full channel · Instagram reels

AI

16 months at Deck on a production agent fleet. 356 tickets, ~100 PRs merged, 134 reviewed.

We basically built our own Lemma. agent-trace, agent-debugger, agent-viewer, zero-browser. Tracing agent runs to find the failures nobody sees. Same problem you sell. So I'm your user.

My own thing: an AI receptionist for barbershops. Cold called 715 shops off the Places API. Nobody bit yet.

Events I produced

• 
  “WTF is an AI Agent?” workshop

  Co-run at the Deck office. I taught the application half. A friend filmed it, I edited and posted the 10 clips.
• 
  Workshop, second edition · 20 Sept 2026

  Came out of a UBC co-working session. People kept asking for it, so we ran it again.
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  MTL speed dating — wine & cheese · July 2026

  25 people. Me and my co-host came up with it, ran it at our office at Deck. I did street outreach, Reddit and Luma. We split food, photos and hosting.
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  Unemployed Builders Club · July 2026

  Foil Gallery · 14 people. My partner got us the venue. We split promo and hosting.
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  Steak Night · 8 Aug 2026

  My roof · 7 people. Texted everyone that morning. Grabbed the ingredients at the grocery store and did it that day.

Before that