Rate limiting (IP address): legitimate interest (Art. 6(1)(f)) — protecting the site from abuse
Contact Form
When you submit our contact form, your data is sent to Ceren via email (through Resend) and stored in our lesson management system (Coda) so we can respond to your inquiry and manage lesson bookings.
WhatsApp
When you message us on WhatsApp, your messages are processed through the WhatsApp Business API (Meta) and stored in our lesson management system (Coda) for student communication and lesson coordination.
Payments
Lesson payments are processed by Stripe. We do not store your payment card details on our servers. Stripe handles all payment data according to PCI DSS standards. Payment records are retained for 10 years as required by German tax law (§147 AO).
Who Processes Your Data
We use the following services to operate this website:
Vercel — website hosting and serverless functions (USA, EU edge network)
Resend — sending email notifications (USA)
Coda — lesson management and student records (USA)
Stripe — payment processing (USA/EU)
Meta / WhatsApp — messaging (USA/EU)
International Transfers
Some of our service providers are based in the United States. Data transfers are protected by the EU-US Data Privacy Framework (DPF) or Standard Contractual Clauses (SCCs) as required by DSGVO.
How Long We Keep It
We don't keep data longer than necessary:
Contact form submissions: until the student relationship ends, plus 6 months
Email notifications: automatically deleted after 30 days (Resend)
WhatsApp messages: until the student relationship ends, plus 6 months
Payment records: 10 years (German tax law, §147 AO)
Theme preference: stored in your browser until you clear it
Cookies & Local Storage
This website does not use tracking cookies. We use Umami for anonymous page analytics (no cookies, no personal data). We store only:
Your dark/light mode preference (localStorage — stays in your browser)
Whether you dismissed the cookie notice (localStorage)
We do not use Google Analytics, Facebook Pixel, or any cookie-based tracking tools. Umami analytics is cookieless and collects no personal data.
If you believe your data has been processed unlawfully, you have the right to file a complaint with the supervisory authority:Der Hamburgische Beauftragte für Datenschutz und Informationsfreiheit Ludwig-Erhard-Str. 22, 20459 Hamburg
Changes to This Policy
We may update this privacy policy from time to time. The date at the top of this page shows when it was last revised.