Privacy Policy

Last updated: November 8, 2025

1. Introduction

Welcome to AlgoArena ("we," "our," or "us"). We are committed to protecting your personal information and your right to privacy. This Privacy Policy explains how we collect, use, disclose, and safeguard your information when you use our competitive coding platform.

2. Information We Collect

2.1 Account Information

When you create an account, we collect:

  • First name and last name
  • Email address (verified via email verification code)
  • Username (unique identifier)
  • Password (encrypted with industry-standard encryption)
  • Skill level (used to set initial ELO rating)
  • Newsletter preferences (general newsletter and/or performance digest)

2.2 Profile Information (Optional)

You may optionally provide:

  • Profile picture (stored in Firebase Storage)
  • Bio (maximum 250 characters)
  • Location (city, state, country)
  • Social links (GitHub, LinkedIn, personal website)

2.3 Coding Activity Data

We automatically collect data about your coding activity:

  • All code submissions (full source code, programming language)
  • Test results (passed/failed tests, runtime, memory usage)
  • Problem solving history and timestamps
  • Practice session data and completion times
  • AI analysis requests and generated feedback
  • Interview session transcripts and voice interactions

2.4 Battle and Competition Data

During competitive battles, we collect:

  • Battle results (win/loss/forfeit/timeout)
  • ELO rating changes and match history
  • Opponent information (username, ELO, match outcome)
  • Battle statistics (streaks, average solve times)

2.5 Keystroke and Typing Pattern Data

During battles only, we collect detailed keystroke timing and code editing patterns for anti-cheat detection and research purposes:

  • Keystroke timing (milliseconds between key presses)
  • Code evolution snapshots (periodic captures of your code)
  • Typing patterns (speed, pauses, deletions, backspaces)
  • Test run frequency and results during the battle
  • Syntax errors and debugging patterns
  • Code length changes over time
  • Typing burst detection (rapid code insertion)

This data is linked to your user ID and email and is used for platform improvement, anti-cheat measures, and research into coding behaviors. Data is collected automatically during every battle.

2.6 User Preferences

We store your preferences including:

  • Battle invitation settings
  • Match found notifications
  • Rank change notifications
  • Forfeit confirmation preferences
  • Show opponent progress setting
  • Practice timer preferences
  • Default programming language
  • AI interviewer preferences (gender, voice, mode)

2.7 Device and Technical Information

We automatically collect:

  • IP address
  • Browser type and version
  • User agent string
  • Screen resolution
  • Device type (desktop, mobile, tablet)
  • Operating system
  • Referring website

2.8 Payment Information

Payment processing is handled by Stripe. We do not store your credit card information on our servers. We only store your Stripe customer ID and subscription status. Stripe's privacy policy governs the handling of your payment information.

2.9 Newsletter and Email Subscriptions

We collect and store:

  • Email subscription preferences (general newsletter, performance digest)
  • Subscription source (account creation, landing page, dashboard)
  • Subscription timestamps and status
  • Unsubscribe tokens for managing preferences

3. How We Use Your Information

We use your information for the following purposes:

  • To provide, maintain, and improve our services
  • To create and manage your account
  • To facilitate battles and matchmaking
  • To calculate and maintain ELO ratings and leaderboards
  • To detect cheating and ensure fair play
  • To process payments and manage subscriptions
  • To send you notifications about battles, challenges, and platform updates
  • To respond to your comments, questions, and requests
  • To send marketing and promotional communications (with your consent)
  • To analyze usage patterns and improve user experience
  • To comply with legal obligations

4. Sharing Your Information and Third-Party Services

We do not sell your personal information. We may share your information in the following situations:

4.1 Public Information

Your username, profile picture, ELO rating, battle history, and coding statistics are publicly visible on leaderboards and your profile page. Other users can view your public profile information.

4.2 Third-Party Service Providers

We share information with the following third-party service providers who help us operate our platform:

Firebase/Google Cloud Platform

Authentication, Firestore database, Cloud Functions, Cloud Storage, Firebase Analytics

Data shared: All user data, code submissions, battle data, preferences

Stripe

Payment processing for subscriptions

Data shared: Email, name, payment information (handled directly by Stripe)

SendGrid (Twilio)

Email delivery for verification codes, transactional emails, and newsletters

Data shared: Email address, name, subscription preferences

DeepSeek AI

AI-powered code analysis, complexity analysis, hints, and AI chat tutor

Data shared: Your code submissions, problem descriptions, coding patterns for analysis

OpenAI

Text-to-speech for AI interviewer (alternative TTS provider)

Data shared: Interview dialogue text for voice synthesis

Cartesia

Primary text-to-speech provider for AI interviewer voice interactions

Data shared: Interview dialogue text for voice synthesis

Judge0 (via RapidAPI)

Code execution engine supporting 60+ programming languages

Data shared: Your code submissions, test cases, programming language for execution

Vercel Analytics

Website usage analytics and performance monitoring

Data shared: Page views, performance metrics, anonymous usage patterns

Google AdSense

Advertising network for displaying ads

Data shared: Anonymous browsing behavior, page visits (managed by Google)

Each of these service providers has their own privacy policies governing how they handle data. We encourage you to review their policies.

4.3 Analytics and Tracking

We use Firebase Analytics, Vercel Analytics, and Google AdSense for tracking website usage, performance monitoring, and advertising. These services may use cookies and similar tracking technologies.

4.4 Legal Requirements

We may disclose your information if required by law or in response to valid requests by public authorities, court orders, or legal processes.

5. Data Security

We implement appropriate technical and organizational security measures to protect your personal information. However, no method of transmission over the Internet or electronic storage is 100% secure. While we strive to protect your information, we cannot guarantee absolute security.

6. Your Privacy Rights

You have the following rights regarding your personal information:

  • Access: You can request a copy of your personal data, including all code submissions, battle history, and keystroke data
  • Correction: You can update or correct your information in your account settings page
  • Deletion: You can request deletion of your account and associated data. Note that some data may be retained for legal or operational purposes
  • Opt-out: You can unsubscribe from marketing emails at any time using the unsubscribe link in emails or through your account settings
  • Data Portability: You can request your data in a portable format (JSON or CSV)
  • Newsletter Management: You can manage your newsletter preferences (general newsletter and/or performance digest) separately
  • Object to Processing: You can object to certain types of data processing, though this may limit platform functionality

To exercise these rights, please contact us at contact@algoarena.net. We will respond to your request within 30 days.

7. Cookies and Tracking Technologies

We use cookies and similar tracking technologies to track activity on our platform and store certain information:

  • Essential Cookies: Required for authentication, session management, and core platform functionality
  • Analytics Cookies: Firebase Analytics and Vercel Analytics to understand how users interact with the platform
  • Advertising Cookies: Google AdSense for displaying relevant advertisements
  • Preference Cookies: Remember your settings and preferences (theme, language, notifications)

You can instruct your browser to refuse all cookies or to indicate when a cookie is being sent. However, if you do not accept cookies, you may not be able to use some portions of our platform, particularly authentication and personalized features.

8. Children's Privacy

Our platform is not intended for children under 13 years of age. We do not knowingly collect personal information from children under 13. If you believe we have collected information from a child under 13, please contact us immediately.

9. International Data Transfers

Your information may be transferred to and processed in countries other than your country of residence. These countries may have data protection laws that are different from the laws of your country. We ensure appropriate safeguards are in place to protect your information in accordance with this Privacy Policy.

10. Changes to This Privacy Policy

We may update this Privacy Policy from time to time. We will notify you of any changes by posting the new Privacy Policy on this page and updating the "Last updated" date. You are advised to review this Privacy Policy periodically for any changes.

11. Contact Us

If you have any questions about this Privacy Policy, please contact us: