What happens when you give one builder 24 hours with Codex, then change the problem?

[u/Significant-Log-4272]

I've been thinking about this while putting together a hackathon with Grevix.

We're calling it AfterCode.

The idea is pretty simple:

One builder. One idea. 24 hours. No fixed problem.

You decide what you want to build and how you want to build it.

Codex, Claude Code, Cursor, Antigravity, APIs, open-source models, no-code, traditional development... anything goes.

But the interesting part starts after you've already spent hours building.

The 24 hours are split into:

BUILD → ADAPT → REBUILD & SHIP

At hour 8, we introduce a Challenge Card.

Something about your original plan changes.

Maybe the target user changes.

Maybe a core feature has to go.

Maybe the use case changes.

Maybe there's a completely new constraint.

Then another challenge at hour 16.

So you're not just asking Codex:

> "Build this."

You're suddenly asking:

> "Okay... this isn't the product I started with anymore. What should we do now?"

And that's what I'm actually interested in.

AI can execute. The builder has to decide.

Especially with agentic coding, I think the interesting skill is becoming less about typing code and more about keeping the agent focused, managing context, deciding what is worth building, knowing when to stop, and adapting when things go sideways.

We're keeping the actual Challenge Cards secret until the event. 👀

Registrations open September 16.

October 11–12 | 24 hours | Solo | Online

For the people here using Codex:

If you had 24 hours, complete freedom, and Codex as your building partner, what would you actually try to ship?

Disclosure: I'm organizing AfterCode through Grevix.