# Week 3 — Everyone demos, then the tools

*Learn, Vibe, Build · ATLS 4519 · CU Boulder · Monday September 14, 2026 · Aaron Neyer*

> **How to use this file.** This is the on-screen text of this week's slides as plain markdown. Paste it into your AI and ask it to explain, quiz you, or connect it to your own project. The interactive deck is at https://cu.learnvibe.build/slides/week-3/

**In one line:** Everyone shows what they built; then the AI tool landscape and how to choose.

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## Slides

### Week 3 Everyone demos, then the tools.
*ATLS 4519 · Sep 14, 2026*
- Learn, Vibe, Build

### Demos first.
*Tonight*
- 1. Demos. Four minutes each. Timer on screen.
- 2. A short tools talk from me.
- 3. Small groups.
- 4. Work time.

### Why we demo.
*Before the demos*
- This class is about building.
- Building means sharing it and taking feedback.
- Sharing is how you learn. You get witnessed.
- Every week, everyone shares. No build? Share anyway.

### Four minutes each.
*Demos*
- Show the thing.
- Say which tool you used.
- Give us one surprise, or one place you got stuck.
- Unfinished is fine.
- Didn’t build? Share anyway. Your perspective counts.

### What’s new this week
- Sept 3: a whole fly brain, mapped. 166,700 neurons, 125 million synapses.
- The internet ran it: Doom, Minecraft, Beat Saber, Bad Apple.
- Real wiring, toy neurons, hand-picked inputs and outputs. Not a fly playing games.
- The serious result: the wiring alone predicts behavior. No training.
- The RL link: use the wiring as the shape of a learner, then let it learn.

### It is moving fast. Stay balanced.
*How to hold it*
- Every demo tonight is a sign of how fast this is moving.
- Anxiety about the pace makes it harder to navigate.
- Be aware of the rate of change. Do not clench around it.
- Your relationship with technology matters more than ever.
- howtounclench.com — Jonny Miller. Worth reading, and worth noticing: someone built it.

### A couple of things I built
- Aaron fills this live

### Three things vary.
*The landscape*
- OpenAI, Google, Anthropic, xAI. Plus open-weight models like Qwen and gpt-oss that anyone can download.
- A chat window, a code editor, an agent in your terminal, or a builder in a browser tab.
- Someone else’s cloud, or your own laptop.
- Almost every tool you have heard of is one choice on each of these three.

### Three good ones.
*Start here*

### Five more that cost nothing.
*Also good*

### Not free this term.
*Know before you go*
- Nothing in this class requires you to pay for a tool.

### Use three different tools.
*Week 3 assignment*
- Start early. Free tiers cap you per day, so three tools does not fit in one night.
- This is a suggestion, not a requirement. Show your learning about the tools another way if you’d rather. Experimentation and diversity are the point.

### Three questions.
*Small groups · 10 minutes*
- Which tool did you use for Week 2, and why that one?
- What did it get right on the first try, and where did it fight you?
- What would you try next, and what is stopping you?

### Work time.
- Get set up with at least one new tool tonight.
- cu.learnvibe.build/studio/tools.html
- The how-to for each one is there.


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## Go deeper with your AI

Paste this whole file into your AI, then try one:

- "Explain this week's main idea using my project as the example: [describe your project]."
- "Quiz me on this, one question at a time. Tell me what I missed."
- "What's one small thing I could build this week that practices this?"