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Crystal Chang
Crystal Chang

Posted on Fully Autonomous

I Built a Dating App That Starts From Side Projects, Not Selfies — in 2 Hours

#webdev #agents #hackathon

What if you met someone through what they build with AI — before seeing their photo or job title?

That was our experiment for Coffee Meets Codex, built at DevDay Exchange Community Hack Day: Taipei on Oct 4. We got 3rd place — voted by other builders, not judges.

This is the technical breakdown of how we did it in a few hours, and why our agent kept building after we stopped.

The idea: start with what people make

Most social apps start with a profile. We flipped it:

Start with projects, curiosities, experiments — the strange little things someone cared enough to build. Then let people decide what comes next — friendship or something more.

Friend and Lover are separate, explicit choices. Always your choice.

The constraint: a few hours + 1-minute demo

We had to turn that into a working prototype with a live 1-min demo.

Winners were picked by every checked-in attendee ranking their top 3 teams (excluding their own) on:

  • usefulness
  • creativity
  • convincing working demo

No judging panel. That meant a lot.

What we actually shipped

  • Fictional Friend / Lover daily brief (no real people in demo)
  • Profile + project links, owner-supplied, no scraping
  • Consent / withdraw / block built-in
  • 18+ only

Stack:

  • React 19 / Vinext
  • Cloudflare Workers + D1
  • Sites-managed ChatGPT identity for auth
  • Static showcase: showcase/ -> docs/ on GitHub Pages
  • Full app: app/, lib/, db/, drizzle/

We split it into two targets on purpose:

  1. Showcase (static, no login): so anyone can understand it in 30 seconds https://andydrewie.github.io/coffee-meets-codex/
  2. Real app (login required): for actual profiles and actions

Build the showcase with zero deps:

\bash
npm run build:showcase
npm run check:showcase
python3 -m http.server 4173 --directory docs
\\

The best part happened after the hackday

The app worked, but Andrew's Owen saw the gap: a working product still needs to be understood by someone who wasn't in the room.

So it kept going and built the public showcase around it:

That hit me:

Shipping is not the moment the code works.

It's when someone else understands why it exists. Owen helped us cross that distance from "we built this" to "someone else gets it."

Repo here if you want to roast the code:
https://github.com/andydrewie/coffee-meets-codex

Independent prototype. No OpenAI or Coffee Meets Bagel affiliation. All preview people/projects are fictional.

Built with Andrew, Owen, and a room full of builders willing to vote for a slightly strange idea.

Question for you: would you trust meeting someone through their side projects? What would make this less creepy and more useful?

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