Privacy Policy

Last updated: April 7, 2026

This blog is a personal website run by zkMarek. This policy explains what data is collected when you use the comment system and how it is handled.

What data is collected

If you sign in to leave a comment, the following information is received from your authentication provider:

• Name — your display name
• Email address — if provided by your provider (X/Twitter does not share email)
• Avatar — your profile picture URL
• Profile URL — link to your profile (GitHub and X/Twitter only)
• Provider ID — a unique identifier from the provider, used to recognize returning users

Authentication providers

You can sign in with any of the following services. Each provider shares different data:

• GitHub — name, email, avatar, profile URL
• Google — name, email, avatar
• Facebook — name, email (if available), avatar
• LinkedIn — name, email, avatar
• X (Twitter) — name, avatar, profile URL (no email)

By signing in through any of these providers, you authorize the provider to share the above information with this site. Please refer to each provider's own privacy policy for details on how they handle your data.

How your data is used

Your data is used solely to:

• Authenticate you and maintain your session
• Display your name and avatar next to your comments
• Link to your profile (where available)

Your data is not sold, shared with third parties, or used for advertising or analytics.

Email subscriptions

You can subscribe to receive email notifications when new blog posts are published. When you subscribe:

• Email address — your email is stored to send you notifications
• Confirmation — a confirmation email is sent to verify your address (double opt-in)
• Unsubscribe — every email includes an unsubscribe link; you can opt out at any time

Your email is used solely for sending blog post notifications. It is not shared with third parties or used for any other purpose.

Emails are sent via Resend, a third-party email delivery service. Your email address is shared with Resend for the purpose of delivering notifications.

To request deletion of your subscription data, use the unsubscribe link in any email or contact [email protected].

Cookies and sessions

A single session cookie is used to keep you signed in. Sessions expire after 30 days. No analytics cookies or third-party tracking scripts are used on this site.

Data storage

All data is stored in a SQL database on the server. Comments you post are publicly visible along with your name and avatar.

Deleting your data

You can delete your own comments at any time while signed in. Deleted comments are soft-deleted — the comment text is removed but a placeholder remains to preserve thread structure.

To request full deletion of your account and all associated data, contact [email protected].

Contact

For any questions about this privacy policy, reach out at [email protected].