This site sells one book. It is not an advertising business, and it does not want your data for anything except sending you what you paid for.
These pages set no cookies, and there is no consent banner because there is nothing to consent to. They do run one piece of analytics, Cloudflare Web Analytics, which counts visits and page views. It sets no cookies and collects no personal data. Reading a page involves two third parties: Cloudflare, for those analytics, and Google Fonts, which serves the fonts, so Google sees the request your browser makes for them.
The site is hosted on GitHub Pages, which keeps standard server logs including IP addresses, in the same way every web server on earth does.
Checkout is handled entirely by Stripe. Your card details go to Stripe and never touch this site. What comes back to us is your email address, your name if you gave it, the country used for tax, and the fact that you bought the book.
That is kept so the purchase can be honoured: proving you own the book, resending it, fixing a failed download, and meeting the tax and accounting obligations that come with selling something.
After you pay, a small service run on Cloudflare asks Stripe to confirm the payment and creates your private link to the files, which are stored with Cloudflare. All that is kept for that link is Stripe's reference for your purchase and the date.
You get a receipt, and you get a message if something about the book materially changes, such as a new edition you already own. You are not added to a marketing list by buying. If a newsletter ever exists, it will be something you opt into deliberately, and one click will end it.
You can ask what is held about you, ask for it to be corrected, or ask for it to be deleted. Reply to your receipt and it will be dealt with. Some purchase records have to be kept for tax purposes even after a deletion request; that part is not discretionary.
Kaloyan Vasilev is responsible for this site and the data it handles. Reply to any email from it and it reaches a person.