Privacy Policy
Last updated: 15 September 2026
The short version. No advertising, no tracking pixels, no third-party cookies, and nothing that follows you around. We count how many times the public pages are opened — a number per day, with nothing stored about who — and after a purchase we keep your email address, the order, and the country on your billing address so we can give you access and answer support questions. That is the whole picture.
Who is responsible
Valerii Boiko, sole proprietor registered in Ukraine, is the data controller for this website. Contact: valera.boyko.01@gmail.com.
What we collect
- Your email address
- Provided by you at checkout and passed to us by Paddle. Used to send your access link and to answer support requests. Legal basis: performance of the contract.
- Purchase record
- Transaction ID, Paddle customer ID, amount and currency, and the date. Used to prove a purchase, to process refunds, and for our own tax records. Legal basis: contract and legal obligation.
- Your access token
- A random string generated by us that acts as your key to the course. It is not derived from anything about you.
- A count of course opens
- How many times your link has been opened, and when it was first and last used. Used to tell an unused link from an active one when someone writes in for support. No page-by-page reading history is recorded.
- A count of page views
- We keep a running number of how many times the public pages were opened each day, and how many of those were the first view in a browser session. This is a counter, not a record: no cookie, no identifier, no IP address and no browser details are stored, and nothing in it can be traced back to a person or linked to a purchase. Legal basis: legitimate interest in knowing whether the site is being read.
- The country on your billing address
- Provided to us by Paddle after a purchase, so we know which countries buyers are in and can check the tax that was applied. Legal basis: contract and legal obligation.
What we do not collect
- Card details. These are handled entirely by Paddle. We never see them.
- Analytics products. There is no Google Analytics, no Plausible, no heatmaps, no session recording — only the anonymous daily counter described above.
- Advertising or tracking cookies. This site sets none.
- Your reading behaviour. Which lessons you read, how far you got and how you answered quizzes stay in your own browser and are never sent to us.
Storage in your browser
The course page uses your browser's local storage to remember two things: which lessons you have ticked off, and whether you chose the light or dark theme. This data stays on your device, is never transmitted to us, and disappears if you clear your browser data. It is a convenience feature, not an account.
Who else processes your data
- Paddle.com Market Ltd (Merchant of Record)
- Processes the payment, calculates and remits tax, and issues invoices. Paddle is the controller for the payment data it collects — see Paddle's privacy policy.
- Resend (email delivery)
- Delivers your access link and any support replies sent from the site. Receives your email address and the message content.
- Our server
- A virtual server rented in Germany, administered by us. The purchase database lives there and is not shared with anyone else.
We do not sell, rent or trade your data, and we do not use it to train anything.
How long we keep it
Purchase records and email addresses are kept for as long as your access is active, and afterwards for as long as tax law requires us to retain records of a sale. You can ask us to delete your access record earlier; this ends your access to the course.
Your rights
Depending on where you live, you may have the right to ask for a copy of the data we hold about you, to correct it, to have it deleted, to restrict or object to its processing, and to receive it in a portable form. To exercise any of these, email valera.boyko.01@gmail.com. We will respond within 30 days.
If you are in the EU, EEA or UK and believe we have handled your data improperly, you also have the right to complain to your local data protection authority.
Security
The site is served over HTTPS. Your access link is a long random token, is marked so search engines do not index it, and can be revoked and reissued if it leaks. Payment card data never reaches our systems.
No system is perfectly secure. If we ever become aware of a breach affecting your data, we will tell affected buyers by email.
Children
This course is aimed at working software developers and is not directed at children under 16. We do not knowingly collect data from them.
Changes
If this policy changes, the date at the top changes with it. Changes that materially affect how we handle existing buyers' data will be announced by email.