William Ragnarsson — Portfolio

Hi, I'm William.

I'm a CS student who can't stop building things. I trained an AI to think like a VC, I fly across Europe for hackathons, and I once tried to start a hardware company. Here's some of it.

Reach out GitHub LinkedIn

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01 — The internship

I did an internship at Plug & Play in San Francisco.

It's one of the world's most active startup accelerators, and I spent it as a VC intern — reading hundreds of pitch decks, sitting in deal reviews, and slowly building an instinct for what makes a startup actually investable. Then, because I'm an engineer, I tried to bottle that instinct.

So I built an AI VC-analyst.

A founder pastes a deck; the model scores it the way a partner would. The part I'm proud of isn't the app — it's that I trained my own model on my own data. I hand-labeled 765 startups, trained a gradient-boosting classifier, and exported it to ONNX so it runs right in the browser.

765
decks I labeled by hand
80.9%
model accuracy
0
Python at runtime (ONNX)
The analyzer How I trained it

02 — Hackathons

I also really love hackathons.

I book the flight first and figure out the project on the plane. Scroll along with me — four countries, four builds, a couple of awards.

New York
Berlin
Stockholm
Belgium
  • New YorkVeil
    flew out
  • BerlinTeam-Zucc
    ★ 3rd place
  • StockholmProject Net Zero
    flew out
  • BelgiumNora AI
    ★ Best Pitch

03 — Everything else

I build a lot of other things too.

Simulators, databases, dev tools, half-finished experiments. Most of it lives on my GitHub — here's a taste.

github.com/william-popmie

04 — Before software

I actually started in hardware.

First year of university, I tried to start my own hardware company. Motors, sensors, PCBs, the whole thing. It taught me a ton — mostly that the part I loved was the software. So I went 100% software. haha.

05 — Say hi

Reach out to me!

I'm always up for ambitious projects, internships, and last-minute hackathon flights.

Emailwilliam.ragnarsson@gmail.comGitHubwilliam-popmieLinkedInwilliam-ragnarsson

© 2026 William Ragnarsson

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