DevDay Exchange Cambridge
Your idea.
Your first build.
A friendly hour with Codex.
No coding experience needed.
Past event
Saturday 17 October 2026
5–6pm BST · University of Cambridge
Hosted by Lili Zhu and Alexandra Tran.
University of Cambridge
Keep your
ideas going.
Thanks for joining us. Keep exploring the workshop resources and take-home challenge.
Keep building.
This workshop took place on 17 October. The take-home challenge is still open until 25 October, 11:59pm UK time.
Continue the challenge ↓
All eligible attendees will receive OpenAI credits.
Keep your
ideas going.
Thanks for joining us. Keep exploring the workshop resources and take-home challenge.
One friendly hour.
See Codex in action, then build Sizing Sprint or a small website of your own.
A quick taste of Appshots.
Show Codex what you’re looking at.
- Welcome and find your dot
- What Codex does + the Ra-mask demo
- Models, usage and resets
- Appshots, live
- Sites and Sizing Sprint, built live
- Your turn: 15 minutes to build
- Show and tell
- Go deeper, take-home challenge and questions
Your workshop kit.
Your first useful build. All 36 slides, with the original design and speaker notes.
Open the slides 36 slides ↗
Editable PowerPoint
Your uploaded deck, including the full host script in Notes.
Download PowerPoint ↓Copy the prompts
Choose your starting point, then make one change and test it.
Go to the hands-on prompts ↓Presentation notes and product caveats
For a one-hour session, keep slides 14–19 brisk or use them for questions. Protect the 15-minute hands-on block. The uploaded PowerPoint is preserved as supplied.
- Slide 16 combines different user metrics, as its speaker notes explain. It is not a like-for-like growth series; the 40 million and 60+ reset headline counts were not independently verified in this review.
- Slide 17: the message ranges are estimates, not guaranteed limits. Astra does not always use exactly three times the allowance. Check your account’s usage dashboard. Current pricing and usage guide ↗
- Slide 20: Appshots may include off-screen text when the app exposes it. This is not guaranteed for every app or page. Appshots guide ↗
- Slide 22: message predictions are a limited beta; availability depends on the plan, region, model and thread. Availability ↗
Copy. Paste. Build.
Choose your dot. Build a first version, ask for one change, then check it. Sample answers are practice material, not real market data.
New · Sizing Sprint
@Sites Build a website where I practise market-sizing questions: a random question, a 3-minute timer, a notes box and a button that reveals a sample answer. Works on a phone.
Tried · Your own idea
@Sites Goal: [what]. Context: [who it’s for]. Constraints: [what to avoid]. Done when: [your test]. Flag anything missing instead of inventing it.
Daily · Make it remember
Add a leaderboard that saves scores in the Site’s database. Offer optional Sign in with ChatGPT so people see their own history. Save a version; don’t deploy.
Sites unavailable on your account? Pair up, or ask Codex for a single index.html file to open locally. Feature access varies by plan and rollout.
One improvement.
One honest check.
Adapt your build to something you care about. Share the prompt, one change and what you tested.
Submit by 25 October, 11:59pm UK time.
Sign in with ChatGPT.
Your entry is private to you and the organiser.