Peponi.to: from AI experiment to live product
The goal was not to ship a product. It was to understand what it means to design and develop with an AI as your pair programmer. The outcome was both.
Problem Statement
The question was whether AI (Cursor) could extend the practice of prototyping in code—design that ships rather than design that gets handed off. Could an LLM help with the scaffolding, the boilerplate, the iterations that slow you down when you are exploring alone?
Todo apps are the hello world of product design. The point was control: you know the domain, you know the edges. You can focus on the process—how does it feel to build this thing with AI assistance?
Your Role and Process
The approach was a controlled experiment: build a Rails todo app with Cursor as a design and development partner. Human design decisions; AI as pair programmer.
Design decisions—flow, feedback, edge cases—stayed human. The AI handled scaffolding and debugging. The failures were instructive: they forced verification of suggestions, understanding of stack traces. The build revealed what AI-assisted development can and cannot do.
Design Solutions
What the AI did well
Scaffolding was the clear win. Generate a Todo model, add a controller, create the views. The boilerplate appeared in seconds. The AI also helped with debugging: paste an error message, get a proposed fix. Often correct, sometimes not. The AI accelerated the cycle of try, fail, fix.
Where it fell short
Design decisions need context. The AI has no memory of previous projects, no intuition about when a pattern fits. It will suggest standard Rails conventions. Sometimes that is right. Sometimes you need to break the convention and the AI will not tell you when. The most valuable takeaway: AI assistance amplifies what you already do well. The tool works best as a pair programmer. Not as a replacement.
The product: Peponi.to
What began as an experiment became something people could use. Peponi.to is now a live web app at peponi.to. Try it free for 7 days, then download to your device forever for £10. No subscriptions. No lock-ins.
Notebook-style design. Hand-drawn aesthetics, typewriter animations, smooth checkbox transitions. Five curated themes: Classic Dotted, Lined Paper, Dark Mode, and more.
Privacy first. No social logins, no big tech tracking, no ads. GDPR compliant. Works completely offline once downloaded.
True data ownership. Download to your device and own your data forever. Works seamlessly as a PWA on phone, tablet, and desktop. No app store required.
Simple by design. Drag-and-drop reordering. No due dates—no stress, just simple lists. Stays logged in like YouTube or Spotify.
Outcomes and Metrics
Live product at peponi.to. A working product that validates a working process.
£10 one-time purchase. No subscriptions, no lock-ins. Download once, own forever.
Privacy-first, works offline. PWA that runs without connection once installed.
Process validated. The design stayed human. The AI was a fast first draft. The result is something people can actually use.
Related reading
- Peponi.to: AI-assisted development — What the AI did well and where it fell short
- Peponi.to: pair programming experiment — Building with Cursor as a pair programmer