Privacy policy
This policy explains what personal data is processed when you visit this website, buy the ebook or contact us, why, and what rights you have. It follows the EU General Data Protection Regulation (GDPR) and Spanish Organic Law 3/2018 (LOPDGDD). We collect as little as possible: this website has no user accounts, no analytics and no advertising.
Who is responsible for your data
- Your Full Name
- 00000000X
- Calle Ejemplo 1, 28001 Madrid, Spain
Payments are handled by Polar (polar.sh), which sells the ebook to you as merchant of record. Polar is an independent controller for the payment, billing and tax data it collects at checkout, under its own privacy policy.
What data we process and why
When you buy the ebook
You enter your details in Polar’s checkout. Polar shares with us the order information we need to deliver the ebook and support you: your name, email address, country, the order and invoice reference, the amount paid, and the record of your consent to immediate delivery. We never receive your full card details.
- Purpose: delivering the ebook, giving access to re-downloads, handling support and refund requests, and keeping records required by tax and accounting law.
- Legal basis: performance of the contract (art. 6.1.b GDPR) and compliance with legal obligations (art. 6.1.c GDPR).
When you email us
We process your email address, name and whatever you include in your message.
- Purpose: answering your question.
- Legal basis: our legitimate interest in replying to messages you send us (art. 6.1.f GDPR), or steps prior to a contract you request (art. 6.1.b GDPR).
When you browse the website
Our hosting provider records technical data such as your IP address, browser type and the pages requested, in server logs kept for a short time for security and to keep the website running (legitimate interest, art. 6.1.f GDPR). We do not use these logs to profile you.
The “try chapter 1 live” playground runs Python entirely in your browser. The code you type is not sent to us. To run it, your browser downloads the Python runtime (Pyodide) from the jsDelivr content delivery network, which receives your IP address as part of that request.
Who receives your data
We do not sell your data or share it for advertising. It is shared only with:
- Polar: checkout, payments, tax, invoices and file delivery (independent controller).
- Stripe: card processing on Polar’s behalf.
- Vercel Inc.: website hosting (processor).
- Our email provider: to receive and answer your messages (processor).
- Tax authorities and courts, when the law requires it.
International transfers
Some of these providers are based in the United States or process data there. Transfers rely on the European Commission’s adequacy decision for the EU–US Data Privacy Framework where the provider is certified, or on the Standard Contractual Clauses approved by the European Commission.
How long we keep it
- Order records: for as long as Spanish tax and commercial law requires (generally up to six years), then deleted.
- Support emails: while we handle your request and for up to two years afterwards, in case you follow up.
- Server logs: for the short period set by our hosting provider.
Your rights
You can ask to access, correct or delete your data, to restrict or object to its processing, and to receive it in a portable format. Where processing relies on your consent, you can withdraw it at any time. Email hello@example.com from the address linked to your order; we reply within one month.
If you think your data has been mishandled, you can complain to the Spanish Data Protection Agency (Agencia Española de Protección de Datos, aepd.es) or to the authority in your country.
Other information
We do not make automated decisions or build profiles about you. This website is not aimed at children under 14, and we do not knowingly collect their data.
For cookies, see the Cookie policy. If this policy changes, we will update the date at the top of this page.