Founder · 2025 – Present · 🌐 zone-prepa.com
1- Overview
Le Carnet de Prépa is a physical notebook that helps students in French classes préparatoires turn every exercise they solve into a technique they remember. I built the whole business on my own: product design, print-on-demand production, a full-stack e-commerce site, automated payment-to-shipping pipeline, and paid acquisition.
- Role: Founder (solo project)
- Period: 2025 – present
- Stack: Next.js, Netlify, Stripe, print-on-demand API, Make, Meta Ads (Pixel), built with Claude Code
- Results: 340+ sales and €9,000 revenue in the first year, rated 4.9/5 on Trustpilot
2- Context & Motivation
Prépa students solve hundreds of exercises, but most of what they learn from them is forgotten by exam day: the key method, the theorem that unlocked the problem, the mistake not to repeat. Having been through three years of prépa myself (Mathematics & Physics), I wanted a simple, physical tool to capture these insights and review them before tests and competitive exams.
An Instagram account I had created to share advice with prépa students (around 8,500 followers) gave me direct access to the target audience, a way to test the idea, and a first distribution channel.
3- The Product
- A guided method, worked examples of corrected exercises, and 600 guided entries to record a technique, a theorem or a mistake, with its reference and level of importance.
- Designed for students in MP, MPI, PSI, PC, PT, MPSI, PCSI, PTSI and ECG, and also used by mathematics undergraduates.
- Sold at €29.99, printed on demand and shipped across mainland France, with a money-back guarantee.
4- Building the Business
E-commerce website
I designed and deployed a full-stack website (zone-prepa.com) using Claude Code, built with Next.js and hosted on Netlify.
End-to-end order automation
Every order runs without manual intervention:
- The customer pays through Stripe.
- A Stripe webhook triggers the order creation.
- The order is sent automatically to a print-on-demand API, which prints the notebook and ships it to the customer.
I also handled the edge cases of the pipeline, such as batching payments and production delays.
Paid acquisition
I ran Meta Ads campaigns myself: budget allocation, audience targeting, Pixel tracking and ROAS/CPA optimization. Key learnings:
- A product demonstration video was by far the best-performing creative; static images did not convert.
- The core buying audience turned out to be women aged 45–54 rather than students themselves, which reshaped targeting and messaging.
Legal & administration
I registered the activity as a sole proprietorship (micro-entreprise) and manage invoicing, customer service and returns.
5- Results
- 340+ sales and €9,000 revenue in the first year
- 4.9/5 customer rating on Trustpilot
- A fully automated sales chain that runs with minimal maintenance
[TO COMPLETE: optional extra figures, e.g. conversion rate, number of reviews, best month]
6- Takeaways
This project taught me to own a product from the first sketch to the customer’s mailbox: talking to users, shipping fast with AI-assisted development, automating operations, and making decisions from real acquisition data rather than intuition.