Privacy Policy

Last updated: 12 November 2026

The short version:

• We collect only what the site needs: your name, your email, a password (stored in scrambled form), and what you do on the sheet (progress, notes, feedback).
• We don't show ads, run analytics or tracking tools, or sell your data.
• Your data is stored in India (Google Cloud, Mumbai).
• You can delete your account, and your data with it, yourself, at any time.

1. Who we are

One-Stop Prep is run by Abhishek Aggarwal, in India. For anything about your data, write to hello@onestopprep.in.

2. What we collect

When you sign up: your name, your email address and your password. We never store the password itself, only a scrambled version (a "hash") that cannot be turned back into it.

What you do on the site: the problems you mark as solved or for revision (and when), the notes you write on a problem, and any feedback message or rating you send us.

To keep you signed in: one cookie called dsa_session. It lasts up to 30 days, the site needs it to work, and it is not used to track you. Your browser also remembers your light or dark choice, on your own device only.

Technical data: our hosting records your IP address and browser details in server logs, for security and for fixing problems. They are kept for about 30 days. We also keep short-lived counters per IP address to stop abuse such as password guessing. They are deleted after about 2 days.

What we don't collect: payment details, phone numbers, your location, or advertising or analytics cookies.

3. How we use it

• to run your account and keep your progress and notes;
• to send the emails the site needs: confirming your email address and resetting your password;
• to read and answer your feedback;
• to keep the site safe and working (blocking abuse, fixing bugs).

We don't use your data for anything else, and we don't send newsletters or marketing emails.

4. AI search

The search bar can answer questions. When it uses Google's Gemini service, we send Google: your question, your last two questions and answers in that chat, matching public parts of the sheet, and one line of counts such as "12 of 247 problems solved". We do not send your name, your email or the text of your notes. Your notes are searched on our own server.

We use Gemini's free service, and under Google's terms for it, Google may use what it receives to improve its products. So please don't type personal details, such as your name, phone number or email, into the search bar.

5. Who else sees your data

We use a few services to run the site:

• Google Cloud: hosting and the database, in Mumbai, India.
• Resend: sends our emails, so it receives your email address, your name and the text of the email. Its servers may be outside India.
• Google Gemini: only as described in section 4.

We don't sell or rent your data. We may share it if a law or a court order requires us to. The sheet links to other websites (LeetCode, YouTube and others). Their own privacy rules apply there.

6. How long we keep it

• Your account, progress, notes and feedback: until you delete your account.
• Sign-in sessions: up to 30 days. Expired ones are deleted every day. Email links (to confirm or to reset) expire quickly and are deleted soon after.
• When you delete your account, your profile, progress, notes, feedback and sessions are removed from our live database straight away. Copies in backups disappear when those backups expire, within about 14 days.

7. Your rights and choices

• Look at and update your information in your account.
• Delete your account from your account menu. You confirm with your password. That removes your data as described above.
• Email us to ask what we hold about you, to have it corrected, or to make a complaint. We will reply within 30 days.
• Under India's Digital Personal Data Protection Act, 2023, you have the right to information about your data, to correction and erasure, to grievance redressal, and to nominate someone to act for you. If our reply doesn't satisfy you, you can complain to the Data Protection Board of India.

8. Age

Anyone can use the site. If you are under 18, please ask a parent or guardian before you sign up and share your details. If you are a parent or guardian and want a child's account and data deleted, write to hello@onestopprep.in and we will delete it.

9. Security

We use HTTPS, store passwords only as hashes, and limit who can reach the database. No system is perfectly safe. If a problem affects your data, we will tell you, as the law requires.

10. Changes

If we change this policy, we will update the date above and, for important changes, email you.

11. Contact

Abhishek Aggarwal · Delhi, India · hello@onestopprep.in