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Cookie Policy

Last Updated: November 2025

1. What Are Cookies

Cookies are small text files that are placed on your device when you visit a website. They are widely used to make websites work more efficiently and provide information to website owners. Cookies help us understand how you use our service and improve your experience.

2. How We Use Cookies

System Design Sandbox uses cookies and similar tracking technologies to provide, improve, protect, and promote our Service. Below is a detailed breakdown of the types of cookies we use and their purposes.

3. Types of Cookies We Use

3.1 Essential Cookies

These cookies are strictly necessary for the Service to function. Without these cookies, certain features would not work.

Authentication Cookies (Clerk)

Purpose: Manage user sessions and keep you logged in

Duration: Session or persistent (based on "Remember me")

Provider: Clerk.com

3.2 Analytics Cookies

These cookies help us understand how visitors interact with our Service by collecting and reporting information anonymously.

PostHog Analytics

Purpose: Track user behavior, feature usage, and performance metrics

Duration: 1 year

Provider: PostHog Inc.

Data Collected: Page views, clicks, session recordings, user properties

Vercel Analytics

Purpose: Performance monitoring and web vitals

Duration: Session

Provider: Vercel Inc.

Data Collected: Performance metrics, page load times

3.3 Functional Cookies

These cookies enable enhanced functionality and personalization.

Theme Preferences

Purpose: Remember your dark/light mode preference

Duration: 1 year

Provider: First-party (System Design Sandbox)

3.4 Local Storage

In addition to cookies, we use browser local storage to enhance your experience:

  • Practice session progress and autosave data
  • User preferences and settings
  • Cached content for faster loading

4. Third-Party Cookies

Some cookies are placed by third-party services that appear on our pages. We do not control these cookies. The third parties include:

5. Session Recording

We use PostHog to record user sessions (screen recordings of how you interact with our Service). These recordings help us identify usability issues and improve the user experience. Session recordings never capture sensitive form inputs like passwords or payment information. You can opt out of session recording by enabling "Do Not Track" in your browser settings.

6. How to Manage Cookies

6.1 Browser Settings

Most web browsers allow you to manage cookie preferences through browser settings. You can:

  • View what cookies are stored and delete them individually
  • Block third-party cookies
  • Block all cookies
  • Delete all cookies when you close your browser

Please note that blocking or deleting cookies may impact the functionality of our Service.

6.2 Browser-Specific Instructions

6.3 Do Not Track

We respect "Do Not Track" browser settings. When enabled, we will not track your session or record your interactions with PostHog.

7. Data Retention

Cookie data is retained for the following periods:

  • Session cookies: Deleted when you close your browser
  • Authentication cookies: Up to 30 days or until you log out
  • Analytics cookies: Up to 1 year
  • Preference cookies: Up to 1 year

8. GDPR and Privacy Rights

If you are located in the European Economic Area (EEA), you have certain rights regarding your personal data collected through cookies. Please see our Privacy Policy for more information about your rights and how to exercise them.

9. Changes to This Cookie Policy

We may update this Cookie Policy from time to time to reflect changes in our practices or for other operational, legal, or regulatory reasons. We will notify you of any material changes by posting the updated policy on this page with a new "Last Updated" date.

10. Contact Us

If you have questions about our use of cookies, please contact us at: privacy@systemdesignsandbox.com