Privacy policy
Effective November 4, 2026 · updated November 5, 2026
In short: you can use every lesson without an account. If you create one, we store your email address, your lesson scores and which lesson sections you have read, so your progress follows you. We don't sell your data, show ads or use tracking cookies, and you can download or delete everything from your account page at any time.
Who we are
Designbench (designbench.dev) is a system design course based in Vancouver, British Columbia, Canada ("Designbench", "we", "us"). We are responsible for the personal information described here. Questions or requests: privacy@designbench.dev.
What we collect
If you don't sign in
- Nothing tied to you. Lessons run entirely in your browser. Quiz answers and which sections you've seen are kept in your browser's own storage (localStorage) and never sent to us.
- Standard request logs kept by our hosting provider, such as IP address, browser type and the page requested, used to run and protect the site and kept only for a short time.
If you create an account
- Account details: your email address and, if you use email sign-in, your password. Passwords are stored only as a salted hash by our sign-in provider; we can't see them.
- From Google or GitHub, if you sign in with them: your email address, name and profile picture link, as shared by that provider. We don't get your Google or GitHub password, contacts, files or repositories.
- Your progress: for each lesson, which sections you have read and the last one you were on, your best score, number of attempts, when you finished it and when you last visited, plus a record of each scored design review (lesson, score, time). Without an account, this stays in your browser (local storage) and is removed when you sign out.
- Sign-in records: when you sign in and from which IP address, kept by our sign-in provider for security.
We don't collect payment details (the course is free), and we don't ask for sensitive information.
Why we use it
- To create your account, sign you in and keep it secure (including stopping abuse, such as limiting how often scores can be submitted).
- To save your progress and show your scores across devices.
- To send emails you need: confirming your address and resetting your password. We don't send marketing email.
- To understand, in aggregate, which lessons are used and how hard the reviews are, so we can improve the course.
We use your information only for these purposes, with your consent when you sign up. You can withdraw that consent at any time by deleting your account.
Cookies and storage
We don't use advertising or tracking cookies. We count visits with Vercel Web Analytics, provided by our host: it sets no cookies and doesn't store your IP address; it records which pages are viewed, the referring site, the country and the type of device, so we can see which lessons people use. Your browser's local storage holds your sign-in session and lesson progress so the site works; clearing your browser data removes it.
If a page crashes, your browser sends us a short error report: the page, the error message, the browser version and which version of the site was running. It contains no account details and is deleted after 90 days.
Who processes your data
We use these service providers, who process data only on our behalf:
- Supabase: accounts, sign-in and the database that stores your progress (servers in the United States).
- Vercel: hosts the website, keeps short-term request logs and counts page views (Web Analytics, no cookies).
- Resend: sends confirmation and password-reset emails.
- Google and GitHub: only if you choose to sign in with them; their own privacy policies apply to your use of their sign-in.
These providers may store and process data in the United States and other countries, where it may be accessible to authorities under local law. We don't sell, rent or trade your personal information, and we don't share it with anyone else unless the law requires it.
How long we keep it
We keep your account and progress until you delete your account. Deleting it permanently removes your account, scores and review history from our database straight away; copies in our provider's encrypted backups expire within their normal backup cycle (days, not months).
Your choices and rights
- Download your data: Account page → Download my data gives you everything we store about you as a JSON file.
- Delete your account: Account page → Delete account. This can't be undone.
- Access or correct anything else, or ask a question: email us and we'll reply within 30 days.
If you're not satisfied with our answer, you can contact the Office of the Privacy Commissioner of Canada or, in British Columbia, the Office of the Information and Privacy Commissioner for BC.
Security
All traffic is encrypted (HTTPS). Database access is restricted so each signed-in user can read and change only their own rows, and the site uses a strict content security policy. No system is perfectly secure; if a breach affects your information we'll tell you as the law requires.
Children
Designbench is meant for people preparing for engineering interviews and isn't directed at children under 13. We don't knowingly collect their information; if you believe a child has created an account, email us and we'll delete it.
Changes
If we change this policy, we'll update the date at the top. If a change affects how we use information you've already given us, we'll tell signed-in users before it takes effect.