Privacy Policy

01 Controller

The controller within the meaning of the General Data Protection Regulation (GDPR) is:

Email

contact@demmler.dev

No data protection officer has been appointed, as there is no legal obligation to do so. Further details can be found in the legal notice.

02 Hosting

This website and all subdomains run on a virtual private server (VPS) that I administer myself. The provider of the server infrastructure is:

The servers are located in data centres in Germany. STRATO only provides the technical infrastructure; all services (e.g. web server and Git service) are installed, configured and operated by me. All data arising from visits to this website is processed on this server.

A data processing agreement pursuant to Art. 28 GDPR is in place with STRATO. It ensures that STRATO processes personal data only on my instructions and in compliance with the GDPR.

The legal basis is Art. 6(1)(f) GDPR. My legitimate interest lies in the secure, reliable and efficient provision of my website.

03 Provision of the website and server log files

When you access this website or a subdomain, your browser automatically transmits information to the server. The web server stores this information in so-called server log files:

• IP address of the requesting device
• Date and time of access
• Requested page or file (including request method and protocol)
• HTTP status code (e.g. “successful” or “not found”)
• Amount of data transferred
• Referrer URL (previously visited page), if your browser transmits it
• Browser type and version as well as operating system (user agent)

Purpose

Processing is necessary to deliver the website, to ensure the stability and security of the server (e.g. to detect and fend off attacks) and to analyse technical errors. The data is not combined with other data sources, evaluated for marketing purposes or used for profiling.

Legal basis

Art. 6(1)(f) GDPR. My legitimate interest follows from the purposes stated above.

Storage period

The log files are rotated daily and automatically deleted after 7 days at the latest. The same applies to the logs of the other server services (e.g. Git service and system log). Individual entries are only kept longer in exceptional cases, if they are needed to investigate a specific security incident, and only until the incident has been resolved.

Necessity

Collecting this data is technically essential for providing the website. Without it, the website cannot be accessed.

04 SSL/TLS encryption

All pages and subdomains are delivered exclusively via an encrypted HTTPS connection. You can recognise the encrypted connection by “https://” in the address bar and by the padlock icon in your browser. This prevents third parties from reading the transmitted data.

05 Cookies and local storage

Cookies are small text files that your browser stores on your device.

Website (demmler.dev): No cookies are set. JavaScript is only used for visual effects (animated background, image enlargement) and for switching the language; no data is transmitted to third parties in the process.

Language selection: If you choose a language using the language switch, this choice is saved in your browser's local storage (entry lang with the value de or en) so that it is kept for your next visit. If you make no choice, the language follows your browser's language setting and nothing is stored. The entry remains on your device and is not transmitted to the server. Storing it is permitted without consent under Section 25(2) no. 2 TDDDG, as it is strictly necessary for the function you have explicitly requested. You can delete the entry at any time in your browser settings.

Git service (git.demmler.dev): Only technically necessary cookies are used (details in section 06). Storing them is permitted without consent under Section 25(2) no. 2 TDDDG, as they are strictly necessary to provide the service you have requested.

No analytics, tracking or marketing cookies are used. A consent banner (“cookie banner”) is therefore not required.

You can delete or block cookies in your browser settings at any time. If technically necessary cookies are blocked, the Git service may only be usable to a limited extent.

06 Git service (git.demmler.dev)

At git.demmler.dev, I run an instance of the open-source software Gitea on my own server, which I use to manage my own software projects and to make some of them publicly available. Third parties cannot register; logging in is reserved for me as the operator.

When you visit the Git service, the access data listed in section 03 is processed. In addition, Gitea logs requests in its own log files (IP address, time, requested path, status code). These are also deleted after 7 days at the latest.

Technically necessary cookies

The cookies contain no tracking information and are deleted at the end of the browser session or when their technically determined validity expires. If the operator logs in, additional login cookies may be set; visitors are not affected by this. The interface may also store individual display settings (e.g. expanded or collapsed sections) in your browser's local storage; this data remains on your device and is not transmitted to the server.

Legal basis

Storing and accessing information on your device: Section 25(2) no. 2 TDDDG. Further processing is based on Art. 6(1)(f) GDPR; my legitimate interest lies in the secure and functional operation of the Git service.

No external content

The Git service is configured so that no content is loaded from third parties. In particular, no external profile pictures (e.g. Gravatar), no external captcha services and no third-party login (OAuth) are used.

07 Contacting me

By email

There is no contact form. If you send me an email at contact@demmler.dev, I process the data you provide: your email address, your name if given, the content of your message, any attachments and the time of receipt.

My mailbox is hosted by Proton AG, Route de la Galaise 32, 1228 Plan-les-Ouates, Switzerland. The data processing agreement pursuant to Art. 28 GDPR is part of Proton's terms of service. The European Commission has recognised Switzerland as providing an adequate level of data protection (Art. 45 GDPR).

The purpose is handling your enquiry. The legal basis is Art. 6(1)(b) GDPR if your enquiry relates to a contract or its initiation (e.g. a project enquiry), otherwise Art. 6(1)(f) GDPR (legitimate interest in answering enquiries).

Storage period: I delete your data as soon as your enquiry has been fully dealt with and no further communication is expected. If the correspondence is subject to statutory retention obligations – for example business correspondence relating to an assignment (Section 147 of the German Fiscal Code, AO) – I keep it for the legally required period and delete it afterwards.

Providing your data is voluntary; however, I cannot reply without an email address. Please note that emails are usually only encrypted in transit, not end-to-end.

By post

Post sent to the address above is received by my service provider Matthias Dully – flexdienst, Kurt-Schumacher-Straße 74, 67663 Kaiserslautern, Germany. Letters are opened, scanned and sent to me by email as PDF files. The provider deletes the scans after 30 days unless the law requires longer retention, and destroys the paper originals 180 days after scanning unless I ask for them to be forwarded or kept. Parcels are not opened: I receive a photo of the parcel by email, and it is forwarded or returned only on my instructions. The provider processes the post on my behalf under a data processing agreement pursuant to Art. 28 GDPR; the data is stored in Germany. For the purpose, the legal basis and how long I keep the post myself, the information on contact by email applies accordingly.

08 Links to external websites

This website contains links to external services, for example LinkedIn, Upwork or a university video portal. Merely visiting my pages does not transmit any data to these providers. Only when you click a link do you leave my website, and the respective provider then processes your data under its own responsibility. Its privacy policy applies.

09 Recipients, third countries and automated decision-making

Your personal data is not sold, not used for advertising and not passed on to third parties. The only recipients are the processors named in this policy (hosting provider, email provider, service provider for receiving post) and – only where required by law – public authorities such as law enforcement agencies.

Data is transferred outside the European Union or the European Economic Area in one case only: emails are processed by Proton AG in Switzerland (see section 07). The European Commission has recognised Switzerland as providing an adequate level of data protection (Art. 45 GDPR).

There is no automated decision-making, including profiling (Art. 22 GDPR).

10 Your rights

With regard to your personal data, you have the following rights:

• Access to the stored data (Art. 15 GDPR)
• Rectification of inaccurate data (Art. 16 GDPR)
• Erasure of your data (Art. 17 GDPR)
• Restriction of processing (Art. 18 GDPR)
• Data portability (Art. 20 GDPR)
• Objection to processing (Art. 21 GDPR, see section 11)

An informal message to contact@demmler.dev is sufficient to exercise your rights.

Right to lodge a complaint with a supervisory authority

Without prejudice to any other remedy, you have the right to lodge a complaint with a data protection supervisory authority, in particular in the Member State of your habitual residence, your place of work or the place of the alleged infringement (Art. 77 GDPR).

11 Right to object under Art. 21 GDPR

12 Changes to this privacy policy

I will update this privacy policy whenever the processing of data changes – for example when new services or subdomains (e.g. game pages or a development journal) are added. The version published here applies.

Last updated: September 2026