Legal
Privacy
Last updated: October 16, 2026.
The controller of your data is GUILHERME DE BRITO OLIVEIRA DESENVOLVIMENTO DE SISTEMAS, a Brazilian company (CNPJ 33.639.852/0001-82) based in Natal, RN, Brazil. Contact: support@systemdesignfactory.com.
Without an account
Your Attempts and Sandboxes stay in your browser. Nothing leaves your device except feedback you choose to send, which carries no identity.
With an account
- Your email, to sign you in and to write to you about your account.
- Your Attempts and Sandboxes, with their notes and titles, to keep them on every device you use.
- Your language, the one you picked, to show the app and write emails in it. Stripe gets it too, for its checkout page.
- Your plan: which plan you have and until when. Card details stay with Stripe.
- “Email me when it arrives”: the Exercises you asked about, until we send that one email.
- Share cards you make: the Exercise or Track, the score, the weak spot and your Design’s shape, never its Components, your name or your email. Anyone with a card’s link can see it; delete it in My progress.
The legal basis is the contract with you (LGPD art. 7, V; GDPR art. 6(1)(b)), and for payment records our legal obligations.
Who processes it
| Service | What | Where |
|---|---|---|
| Clerk | Email and sign-in | United States |
| Neon | Database: account, Attempts, Sandboxes, plan, share cards | United States |
| Stripe | Payments, billing address, receipts | United States |
| Vercel | Hosting, request logs and anonymous page counts (Web Analytics, no cookies) | United States |
| Sentry | Error reports: the page or route, the browser and the code that failed, never your Designs or your email | United States |
| Resend | Sending our emails | United States |
Data sent to the United States is protected by each provider’s data processing terms, with standard contractual clauses.
How long we keep it
While your account exists. When you delete it, we erase it at once from our database, keeping only the random id of your sign-in so a session still open cannot recreate the account; Clerk deletes your sign-in. A share card’s public page and picture can stay in caches for up to a minute after you delete it or the account. Stripe keeps payment records for as long as tax law asks.
Your rights
You can see, download, correct and delete your data. Download and deletion are in My progress → Your data; for anything else, write to us. You can also complain to the ANPD in Brazil or your local data protection authority.
Cookies
We use no advertising or tracking cookies. Sign-in uses the cookies Clerk needs to keep you signed in. Page counts use no cookies and no identifier that follows you.