Privacy Policy

Last updated: March 2026

Derstina ("we," "us," or "our") operates the website and platform at derstina.com. This Privacy Policy explains how we collect, use, store, and protect your information when you use our English language teaching platform.

By using Derstina, you agree to the practices described in this policy. If you do not agree, please do not use our services.

1. Information We Collect

We collect the following categories of information:

Account Information (Teachers)

• Name and email address, collected during account registration
• Authentication credentials managed through Firebase Authentication (email and password)
• Subscription and billing status

Student Information

• Student name
• English proficiency level (CEFR level)
• Native language
• Learning progress and lesson completion data
• Game scores and activity results

Student information is entered and managed by teachers. Students do not create accounts on Derstina.

Payment Information

• Payments are processed by Stripe via a Firebase Extension. We do not directly store credit card numbers, bank account details, or other sensitive payment credentials on our servers. Stripe handles all payment data in accordance with PCI-DSS standards.

Usage and Analytics Data

• We use Google Analytics (gtag.js) to collect anonymous usage data such as pages visited, session duration, device type, browser type, and approximate geographic location. This data helps us understand how our platform is used and improve the experience.

2. How We Use Your Information

We use the information we collect to:

• Provide, maintain, and improve the Derstina platform
• Authenticate your identity and manage your account
• Process subscription payments through Stripe
• Store and display student profiles, progress, and game scores for teachers
• Send important service-related communications (e.g., billing confirmations, account changes)
• Analyze platform usage to improve features and performance
• Respond to support requests

3. How We Store Your Data

Account and student data is stored in Google Cloud Firestore, a part of the Firebase platform operated by Google. Firebase Authentication handles credential storage and user session management.

We implement reasonable technical and organizational measures to protect your data against unauthorized access, alteration, disclosure, or destruction. However, no method of electronic storage is completely secure, and we cannot guarantee absolute security.

4. Data Sharing and Third Parties

We do not sell your personal data to third parties.

We share data only with the following service providers, strictly for the purposes described in this policy:

• Firebase / Google Cloud — authentication, database hosting, and infrastructure
• Stripe — payment processing
• Google Analytics — anonymous usage analytics

These providers process data on our behalf and are bound by their own privacy policies and data protection obligations.

We may also disclose your information if required by law, regulation, legal process, or government request.

5. Data Retention

We retain your account data and associated student data for as long as your account is active. If you delete your account, we will remove your personal data and associated student records from our active systems within 30 days. Some data may persist in backups for a limited period and will be deleted in accordance with our backup retention schedule.

Payment transaction records may be retained as required by applicable tax and financial regulations.

6. Cookies and Tracking

Derstina uses cookies and similar technologies for authentication (keeping you signed in) and analytics (Google Analytics). Google Analytics uses cookies to collect anonymous usage data.

You can control cookies through your browser settings. Disabling cookies may affect your ability to sign in and use the platform.

7. Children's Privacy

Derstina is a platform for English language teachers and tutors. Teachers may enter information about their students, including minors. However, we do not knowingly collect personal information directly from children under the age of 13 (or the applicable age in your jurisdiction). Students do not create accounts or interact directly with Derstina in a way that requires them to submit personal data.

Teachers are responsible for obtaining any necessary parental or guardian consent before entering student data into the platform.

8. Your Rights

Depending on your location, you may have the right to:

• Access the personal data we hold about you
• Request correction of inaccurate data
• Request deletion of your data
• Object to or restrict certain processing of your data
• Request a portable copy of your data
• Withdraw consent where processing is based on consent

To exercise any of these rights, please contact us at the email address listed below. We will respond to your request within 30 days.

9. International Data Transfers

Your data may be processed and stored in countries outside your own, including the United States, through our use of Firebase and Google Cloud infrastructure. By using Derstina, you consent to such transfers. We ensure that appropriate safeguards are in place in accordance with applicable data protection laws.

10. Changes to This Policy

We may update this Privacy Policy from time to time. When we make changes, we will revise the "Last updated" date at the top of this page. We encourage you to review this policy periodically. Continued use of Derstina after changes are posted constitutes your acceptance of the updated policy.

11. Contact Us

If you have questions or concerns about this Privacy Policy or how we handle your data, please contact us at:

Derstina
Email: support@derstina.com
Website: derstina.com