Privacy notice
Who is responsible
Hendrik Mattern is responsible for this personal website. Contact details are in the imprint.
Hosting and access logs
This site is hosted by GitHub Pages, a service of GitHub, Inc. When a visitor opens a GitHub Pages site, GitHub logs the visitor’s IP address for security purposes, whether or not the visitor is signed in to GitHub. GitHub may also receive technical request information needed to deliver the site. GitHub is the hosting recipient of these data. This processing supports the secure and reliable operation of the website (Article 6(1)(f) GDPR). Hendrik Mattern does not receive GitHub’s raw visitor logs. GitHub determines retention according to the purpose and legal obligations and may process data in the United States and other countries; its statement describes the transfer safeguards. See the GitHub Privacy Statement and GitHub Pages documentation.
Site features and third-party links
The site does not use visitor analytics, advertising, comments, or optional tracking cookies. Its styles, scripts, images, and interactive collaboration map are served from this site. When the map loads, Plotly additionally requests its world geography from cdn.plot.ly. That request transmits your IP address and ordinary browser request data to the CDN; the map is provided on the basis of Article 6(1)(f) GDPR. See Plotly’s privacy policy for its data handling and transfer information. The map displays coauthor locations by city, without naming individuals. If you follow an external link, your browser then contacts that destination under its own privacy terms.
Email contact
If you email the address in the imprint, the information you send is used to handle and reply to your inquiry (Article 6(1)(f) GDPR, or Article 6(1)(b) GDPR where your inquiry concerns steps toward a contract). Messages are retained only as long as needed for the inquiry and any applicable recordkeeping duties. Please do not send sensitive personal information unless it is necessary.
Your rights
Where the GDPR applies, you may request access to, correction or deletion of, or restriction of processing of your personal data. You may object to processing based on legitimate interests, request data portability where applicable, and lodge a complaint with a competent data protection supervisory authority. This site makes no automated decisions or profiles of visitors. Use the contact details in the imprint to make a request.
Last updated: September 2026.