Privacy

Last updated 12 October 2026

The short version

No ads, no selling data, no tracking you around the web. We count page views without cookies. Lessons work without an account. If you sign in, we keep your email and your progress so it follows you to every device, and nothing more.

Without an account

Everything stays in your own browser, on this device:

• Your progress: ticked checklists, quiz scores, finished lessons and the last lesson you opened, in your browser's local storage.
• Your theme and the name for your certificate: also in local storage.

With an account

Signing in is optional. When you do, we store:

• Your email address, used to sign you in with a one-time link, and to identify your account. If you sign in with GitHub or Google, we receive your email from them.
• Your name, if you add one, for your certificates.
• Your progress: the same things as above, so they appear on every device you use.
• Your certificates: the name on it, the course and the date. Anyone with a certificate's link can see that page; that is what makes it shareable. There is no list of certificates anyone can browse.
• A sign-in cookie in your browser, so you stay signed in. Signing out removes it from that browser.

Waitlist

Email sign-ups are closed. They open again only once every email carries a confirmation step and a one-click unsubscribe, and addresses not confirmed within 7 days are deleted. If you joined the waitlist earlier, we store your email address and the page you signed up from, have never sent anything to it, and remove it whenever you ask.

Who processes your data

• Supabase hosts the database and handles sign-in, including the sign-in emails.
• Upstash counts requests to stop abuse. A count is keyed by a one-way hash of your IP address or by your account id, never the IP itself, and is kept for an hour at most.
• Sentry receives error reports when something breaks on our servers: which page or request failed and why. No IP addresses, cookies or anything you typed.
• Cloudflare Web Analytics counts page views: which pages, which country, which browser. No cookies, no fingerprinting, and nothing that identifies you.
• Netlify hosts the website. Like any web host, it keeps standard request logs.

Removing your data

• Your progress: clear it any time from My learning. When you're signed in, this clears your account and this browser.
• Your account: delete it from My learning. Your email, name, progress and certificates are deleted straight away, and certificate links stop working.
• Your waitlist email: write to elonerajeev@gmail.com and we remove it.

Questions about your data: elonerajeev@gmail.com.