Building Crayo in 3 Days: From Claude Design to First Paying Stranger

Crayo - AI Coloring Book SaaS

Two euros from a stranger

A few days after I quietly launched crayo.ro, my phone buzzed with a Stripe notification. A complete stranger, someone I had never met or sold to directly, had paid me about 2 euros for a personalized coloring book made from their own photos.

It is a tiny number, but it made me genuinely happy. Someone looked at my product, decided it was worth their money, and paid for it. That is the part I cared about.

What Crayo is

Crayo is a small Romanian-language SaaS that turns any photo into a personalized, AI-generated coloring book PDF. You upload pictures of your kid, your dog, a family moment, anything you want. You pay through Stripe. You get a printable PDF of clean, kid-friendly coloring pages generated from your images. The whole product is in Romanian, priced in lei, targeted at Romanian parents.

Pricing today is intentionally simple: up to 20 photos for 9.90 lei. I am not optimizing for margin at this stage. I am optimizing for the smallest possible price that still requires a real Stripe transaction, so that the first customer is a genuine commercial signal and not a favor from someone who knows me.

Why I built it at all

Honestly, I started Crayo to see what Claude Design could do. Anthropic Labs released it in April 2026 and I wanted a real, end-to-end project to put it through. The plan was to spend an afternoon prototyping the idea, look at the result, and move on.

Once I saw what came out of that afternoon, I decided to ship it instead. I also gave myself a personal challenge: build a SaaS that actually gets at least one paying customer from outside my network. Not friends, not family, not generous coworkers. A real stranger paying real money for a real product. That challenge is what made me push past the prototype and actually ship it.

Three days, end to end

The entire technical build took three days. Domain, frontend, backend, image generation pipeline, payments, deployment, analytics. The timeline is not me being fast. The timeline is the workflow.

Phase 1: Prototyping in Claude Design

I started inside Claude Design, the visual prototyping tool Anthropic Labs released in April 2026. The premise is simple. You describe a product in natural language and Claude builds a first version of the interface. You then refine through conversation, inline comments, direct edits, and custom sliders. It is powered by Claude Opus 4.7, and crucially, the outputs are designed to be handed off to Claude Code for real implementation.

I spent the first chunk of day one in there. I told Claude Design who the customer was, a Romanian parent who wants a personalized coloring book made from photos of their kid, and watched it produce a real, clickable landing page in Romanian: hero, before/after, pricing tiers, FAQ, footer. I refined the layout, tightened the copy, picked the palette, and adjusted the spacing. I ended up with a landing page I would have been embarrassed to build by hand in the same amount of time.

By the end of that session I did not have a one-page spec. I had a working, polished, opinionated front-end prototype, including the visual identity for the brand, sitting in Claude Design and ready to be handed over.

Phase 2: Handoff to Claude Code

Then I handed it to Claude Code and let it build out the rest: pulling the Claude Design prototype into a real Vite + React project, wiring the photo upload, building the Hono backend, integrating Vertex AI Gemini for image generation, hooking up Stripe Checkout, configuring Cloud Run, Firestore, GCS lifecycle rules, the Telegram notification bot, the GitHub Actions deploy to Cloudflare Pages, and the analytics consent flow.

From there it was a loop. I described the next slice of behavior, Claude Code implemented it, I tested it, we iterated. The build proceeded as a sequence of well-scoped tickets, each one small enough to verify before moving on. By the end of day three I had a deployed, payment-accepting product on a custom domain.

The handoff itself was the part I did not expect to enjoy as much as I did. Claude Design produced the surface the customer sees, Claude Code produced everything behind it, and the two tools fit together as one continuous workflow rather than two separate products glued at the seams.

The stack

Nothing here is novel. I picked managed services everywhere I could.

None of these choices are clever. They are deliberately boring, because boring infrastructure is the kind that leaves me alone.

Security, because the product processes children's photos

This part I want to be explicit about. The core use case for Crayo is parents uploading photos of their kids. Some of those photos are family memories that nobody else should ever see. I treated that as a hard requirement from the very first design conversation, not a feature I would add later.

What that looks like concretely:

None of this is exotic. It is the version of "default to safe" that I can live with given what people are uploading.

Why three days is the headline, not the tech

The interesting thing about Crayo is not the stack. The stack is whatever the stack is. The interesting thing is that the cost of going from "I have an idea over morning coffee" to "a stranger paid me for it" has collapsed.

A few years ago, this build would have been a multi-week project. I would have spent days on auth, days on image generation pipelines, days fighting with a payment integration. Today the bottleneck has moved entirely off of typing code and onto the things AI cannot do for me: deciding what to build, talking to real users, understanding the market, and taking the legal risk of putting a business in the world.

What is next

Crayo is at the start of its life. Right now I am in the acquisition phase: running a small Meta Ads campaign, watching the analytics, A/B testing the landing page, and reading every piece of feedback I get from real customers. The next milestone is not a fancier feature. It is the tenth paying stranger, and then the hundredth.

To speed that loop up, I set up a Claude routine that runs every day. It pulls the previous day's ad performance from Meta, drafts new creative, and either tweaks the campaign or makes changes to the crayo.ro site based on what it sees. I am genuinely curious to see how this goes.

That first 2-euro Stripe notification from a stranger is still the part I keep thinking about. It made the whole thing feel real.

If you have kids, a dog, or a memory you want turned into a coloring book, crayo.ro is live. And if you are sitting on an idea wondering whether you can ship it, with the right tools, three days is probably enough.

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