Privacy Policy
Last updated: August 23, 2026
Data Controller
The controller of the personal data collected by pzarycki.pl and pzarycki.com is Piotr Zarycki, who runs this blog as a private individual.
Contact us regarding data matters: [email protected] or via the contact page at .
General Rule
This blog is a personal project; I do not sell anything or engage in profiling. I do not sell or share data for marketing purposes. I collect only what is necessary for the site to function, to maintain it, and so that I know which posts people are reading.
What Data and Why
🌐 Server and CDN Logs
Every visit to the site leaves a record in the logs of the IP address, browser header, address of the requested page, and the time. Traffic passes through Cloudflare, which acts as a CDN and an attack filter.
- Purpose: website maintenance, troubleshooting, and protection against abuse
- Legal basis: legitimate interest (Article 6(1)(f) of the GDPR)
📊 Visitor Statistics
I use Google Analytics 4 with IP address anonymization enabled
(anonymize_ip). The script does not run until consent is given via the banner.
- Purpose: To track which content is being read
- Legal basis: Your consent (Article 6(1)(a) of the GDPR), which you may withdraw at any time by clearing your cookies or installing the Google Analytics opt-out browser add-on
👏 Claps on posts
The “clap” button only saves the counter assigned to the post. To prevent anyone from incrementing it indefinitely, a salted cryptographic hash of the IP address (SHA-256) is stored next to the counter - not the address itself. The hash cannot be reversed back to the address and is not linked to anything else.
- Purpose: to limit the number of claps per person
- Legal basis: legitimate interest (Article 6(1)(f) of the GDPR)
💬 Comments
Comments are powered by Remark42, running on my own server at comments.pzarycki.pl. Your data is not shared with any third-party companies. The scope of the data depends on what you provide when commenting - your name and the content of your comment are public.
- Legal basis: Your consent, expressed by posting a comment
- You can delete your comment by writing to the address provided above
✉️ Newsletter
Newsletter sign-ups are handled by Listmonk, which is also hosted on my server (newsletter.pzarycki.com). I collect only email addresses.
- Legal basis: Your consent
- Each message includes a link to unsubscribe from the mailing list; once you unsubscribe, I will delete your email address
⚙️ Code Playgrounds
On some posts, you can run code written in C or Rust. The code is sent to my server, compiled, executed in a temporary directory, and deleted immediately after the result is returned-it is not saved or viewed anywhere. The number of runs is limited based on the same IP address hash as with claps.
Playground JavaScript runs entirely within your browser and does not send anything.
Data Shared Externally
To be honest: some of the content is loaded from third-party servers, which means that your IP address is sent to them.
| Service | What it does | Where the data goes |
|---|---|---|
| Cloudflare | CDN and security | all traffic |
| Google Analytics | statistics | after consent |
| Google Fonts | fonts | on every visit |
| jsDelivr, cdnjs | JS libraries for the code editor | on pages with the playground |
Google Fonts and CDNs download files directly from external servers, so your IP address is visible to them even without your consent for analytics - this is a technical consequence of loading a file from a different domain. I’m considering moving these resources to my own server to avoid this.
How Long Do I Retain Data?
- Server logs: up to 30 days
- Google Analytics: as per your account settings; 14 months by default
- Shortened URLs from claps: indefinitely, but these are shortened links, not actual addresses
- Email address in the newsletter: until you unsubscribe
- Comments: until you or I delete them
Your Rights
Under the GDPR, you have the right to:
- access your data and receive a copy of it,
- correct your data,
- have your data deleted (“right to be forgotten”),
- restriction of processing,
- data portability,
- objection to processing based on legitimate interests,
- withdrawal of consent at any time, without affecting the lawfulness of processing prior to withdrawal.
To use any of these services, please write to the address provided at the beginning. I will respond within 30 days.
You also have the right to file a complaint with the President of the Personal Data Protection Office (ul. Stawki 2, 00-193 Warsaw, uodo.gov.pl), if you believe that I am processing your data unlawfully.
Cookies
I have provided details about cookies separately in ’s Cookie Policy].
Changes
If I change the way I process the data, I’ll update this document and change the date at the top. It’s a good idea to check back here from time to time.