Terms of use
Last updated: 22 October 2026
These terms cover your use of SDQ. By creating an account or using the site, you agree to them.
The service
SDQ offers lessons, a system simulator, challenges, a reference library and AI mock interviews for learning system design. It is free to use today. We may add, change or remove features, and limit things that cost us money to run, such as mock interviews per day.
Your account
Keep your sign-in email secure; anyone who can open your email can sign in. One account per person. Tell us at saifmd238@gmail.com if you think someone else is using it.
Fair use
Use SDQ to learn. Don’t try to break or overload it, get around its limits, scrape it in bulk, misuse the AI interviewer, or use it to harm others. We may suspend accounts that do.
Content
The lessons, library, challenges, illustrations and code of SDQ belong to us or our licensors; parts of the AI section are adapted from open-source material under its licence. Your notes, designs and answers stay yours; you let us store and show them back to you, and on your public page if you switch it on.
AI and accuracy
Lessons and AI feedback are for learning. They can be incomplete or wrong, and they are not professional advice. Mock-interview scores are practice, not a prediction of any real interview.
No warranty
SDQ is provided as it is, without warranties. To the extent the law allows, we are not liable for indirect losses, or for losses from relying on the content.
Law and contact
These terms are governed by the laws of India. We may update them and will change the date above. Questions: saifmd238@gmail.com.