Privacy Policy

Last updated: 25 June 2026

This policy explains what data Quant Drills (the "Service") collects, why, how it is stored, and the choices and rights you have. We aim to collect as little as possible.

1. What we collect

Account identity. When you sign in with Google we receive your email address, name and Google account identifier. We use these to identify your account and entitlement.
Subscription data. If you subscribe to Pro, our payment processor (Stripe) handles your payment. We store a Stripe customer/subscription reference and your plan/status — never your card number.
Your progress. Which problems you have solved, your spaced-repetition schedule, saved/marked items, playlists and practice history — so it syncs across your devices.
Minimal technical data. Standard request information (such as IP address) is processed transiently by our hosting provider to serve the Service, prevent abuse and rate-limit requests.

We do not sell your personal data, and we do not run third-party advertising.

2. How we use it

To provide and sync the Service, authenticate you, process subscriptions, prevent abuse and fraud, respond to support requests, and meet legal obligations.

3. Service providers

We share the minimum necessary with providers that run the Service on our behalf:

Google — sign-in (you authenticate directly with Google).
Stripe — payment processing and billing.
Cloudflare — hosting, storage (your account and progress), and security.

These providers process data under their own terms and privacy policies.

4. Cookies

We use a single essential, HttpOnly session cookie to keep you signed in. We do not use advertising or cross-site tracking cookies. Your theme and a copy of your progress are kept in your browser's local storage on your device.

5. Storage and retention

Account, entitlement and progress data are stored in Cloudflare's key-value storage. We keep your data while your account is active. When you delete your account we remove your stored entitlement and progress and end your session promptly; billing records held by Stripe are retained by Stripe as required for financial and legal compliance.

6. Your rights

Depending on your location (e.g. UK/EU GDPR, California CCPA) you may have rights to access, correct, export or delete your data, and to object to or restrict certain processing. You can:

Export your progress any time from the Account page.
Delete your account and stored data from the Account page (this is immediate and irreversible).
Contact us to exercise any other right.

7. International transfers

Our providers may process data in countries other than yours. They maintain safeguards intended to provide an adequate level of protection for such transfers.

8. Children

The Service is not directed to children under 16, and we do not knowingly collect their data.

9. Changes

We may update this policy; material changes are reflected by the "Last updated" date above.

10. Contact

Privacy questions or requests: cmbenello@gmail.com.