← Yeongjun Yoo

Writing

Three Losses · 5 parts

1. I thought I was 89th. I was 265th.2026.07

2. I built a bot that collects draws2026.07

3. 14 days of tuning gained 0.05. Two days of research gained 0.08.2026.07

4. Two days after we called it over, I was 30th2026.07

4. After three losses I didn't build a better model. I built a checklist.2026.07

Running My Own Agent Runtime · 4 parts

1. A third of the window was already full before any work started2026.07

2. My markdown folder was already a multi-agent system2026.07

3. My AI erased my records twice2026.07

4. You don't invent the answer. You converge on it.2026.07

WorldQuant BRAIN · 10 parts

1. Trying to ship one alpha, I built an alpha factory2026.06

2. The 0.95 wall, and orthogonality as the honest way through2026.06

3. My first submittable alpha: cash-flow reversion2026.06

4. Multiplying signals, and the real rules of the scoreboard2026.06

5. Outside the family: competitors, options, and their intersection2026.06

6. Building a factory, hitting a wall, then changing the method2026.07

7. Crossing silver, stopped 0.0063 short2026.07

8. Do not multiply, add2026.07

9. The sixth alpha I could not find, and what remains2026.07

10. Past Gold, then across the last 0.052026.07

Other

Filling official HWP forms with code: eight traps2026.07

Press Enter while typing Korean and the message sends twice2026.07

Picking a document parser off a leaderboard is how you get it wrong2026.07

My Vercel deploys were BLOCKED because of the commit author email2026.07