1. Controller
The controller responsible for data processing within the meaning of the GDPR is:
Gerd Brunn
Berlin, Germany
hello@group-challenge.com
2. Data We Collect
When you use Challenger, we collect and process the following data:
- Email address (required for registration)
- Username and display name
- Profile picture (optional, uploaded by you)
- Country of residence (selected during signup)
- Progress data (values and notes you log in challenges)
- Chat messages sent within challenges
- Timestamps of last activity (last_seen_at)
- Technical log data and session cookies
3. Purpose and Legal Basis
Your data is processed solely for the purpose of providing the Challenger service — account management, challenge participation, leaderboards, and chat. The legal basis is Art. 6(1)(b) GDPR (performance of a contract).
4. Third-Party Service Providers
We use the following third-party services to operate Challenger:
- Supabase — database and authentication (servers in the EU). Data processing agreement in place per Art. 28 GDPR.
- Replit — hosting and infrastructure (USA). Data is transferred on the basis of Standard Contractual Clauses (SCCs) per Art. 46(2)(c) GDPR.
5. Data Retention
Your data is stored until you delete your account. You can delete your account at any time from your Profile page. Upon deletion, all personal data is removed and chat messages are anonymised.
6. Cookies
Challenger uses a single session cookie to keep you signed in. No tracking cookies, no advertising cookies, no analytics cookies are used.
7. Your Rights
Under the GDPR, you have the right to:
- Access the personal data we hold about you (Art. 15 GDPR)
- Rectify inaccurate data (Art. 16 GDPR)
- Erasure of your data ("right to be forgotten") — available in-app via Profile → Delete Account (Art. 17 GDPR)
- Data portability (Art. 20 GDPR)
- Object to processing (Art. 21 GDPR)
- Lodge a complaint with a supervisory authority (Art. 77 GDPR) — in Germany: your local Datenschutzbehörde
8. Contact
For any privacy-related questions or requests, contact us at: hello@group-challenge.com