Privacy Policy

Effective Date: January 6, 2026

EngX is developed by Lynera

Welcome to EngX! This Privacy Policy explains how Lynera ("we," "us," or "our") collects, uses, shares, and protects your personal information when you use EngX. By using EngX, you consent to the practices described in this Privacy Policy.

1. Information We Collect

1.1 Account Information

When you create an account, we collect:

Email address
Password (encrypted)
Display name (optional)
Profile information (optional: avatar, bio, location, website)

1.2 Payment Information

When you subscribe to a paid tier, we collect:

Payment card information (processed securely by Stripe; we do not store full card details)
Billing address
Transaction history

Payment processing is handled by Stripe. Please review Stripe's Privacy Policy at https://stripe.com/privacy.

1.3 Usage Data

We automatically collect information about your use of EngX, including:

Problems viewed and attempted
Answers submitted
Time spent on problems
Hint requests and interactions
Performance metrics (accuracy, points, streaks)
Leaderboard rankings
Login and session activity

1.4 Device and Technical Information

We collect:

IP address
Browser type and version
Device type and operating system
Referring website
Pages viewed and time spent on pages
Cookies and similar tracking technologies

1.5 AI Hint Interactions

When you request AI-powered hints, we collect:

Problem context
Your answer (if provided)
Hint level requested
AI-generated hint content
Flagged hints and feedback

2. How We Use Your Information

We use your information to:

2.1 Provide and Improve the Service

Deliver problem-solving challenges and features
Track your progress and performance
Display leaderboards and rankings
Generate personalized analytics
Improve platform functionality and user experience

2.2 Communication

Send account-related notifications (e.g., subscription confirmations, password resets)
Respond to support inquiries
Send platform updates and announcements (you may opt out of marketing emails)

2.3 Payment Processing

Process subscription payments
Manage refunds and billing inquiries
Prevent fraud and unauthorized transactions

2.4 Analytics and Research

Analyze usage patterns and trends
Conduct A/B testing and feature experiments
Generate aggregate statistics (anonymized)

2.5 Security and Compliance

Detect and prevent fraud, abuse, and security threats
Enforce Terms of Service
Comply with legal obligations

3. Third-Party Services

We use the following third-party services to operate EngX:

3.1 Supabase

Purpose: Database and authentication
Data Shared: Account information, usage data, submissions
Privacy Policy: https://supabase.com/privacy

3.2 OpenAI

Purpose: AI-powered hint generation
Data Shared: Problem context, user answers (optional), hint requests
Retention: OpenAI retains data for 30 days for abuse monitoring, then deletes it
Privacy Policy: https://openai.com/privacy

3.3 Stripe

Purpose: Payment processing
Data Shared: Payment information, billing details, transaction history
Privacy Policy: https://stripe.com/privacy

3.4 Google Analytics

Purpose: Website analytics and usage tracking
Data Shared: Device information, page views, session data (anonymized)
Privacy Policy: https://policies.google.com/privacy

3.5 Vercel

Purpose: Hosting and content delivery
Data Shared: Technical logs, request metadata
Privacy Policy: https://vercel.com/legal/privacy-policy

4. Information Sharing and Disclosure

4.1 Public Information

The following information may be publicly visible on EngX:

Display name
Profile information (if provided)
Leaderboard ranking and points
Solved problems (count)
Badges and achievements (if implemented)

You can control some public information visibility through your profile settings.

4.2 Aggregated Data

We may share anonymized, aggregated data (e.g., platform statistics, usage trends) with partners, researchers, or the public.

4.3 Service Providers

We share information with third-party service providers (listed in Section 3) who help us operate EngX. These providers are contractually obligated to protect your information.

4.4 Legal Compliance

We may disclose your information if required by law, court order, or government request, or to protect our rights, property, or safety.

4.5 Business Transfers

If Lynera is involved in a merger, acquisition, or sale of assets, your information may be transferred to the new entity. We will notify you of any such change.

5. Data Retention

5.1 Account Data

We retain your account data as long as your account is active or as needed to provide services.

5.2 Usage Data

Usage data (submissions, hints, analytics) is retained indefinitely for platform improvement unless you request deletion.

5.3 Payment Data

Payment transaction history is retained for legal and accounting purposes (typically 7 years).

5.4 AI Hint Data

AI hint interactions are logged for quality assurance. OpenAI retains data for 30 days, then deletes it. EngX may retain hint logs longer for platform improvement.

5.5 Deleted Accounts

When you delete your account, we will delete or anonymize your personal information within 90 days, except where retention is required by law.

6. Your Rights

Depending on your location, you may have the following rights:

6.1 Access

You can request a copy of your personal information by contacting privacy@engx.com.

6.2 Correction

You can update your account information through your profile settings or by contacting support@engx.com.

6.3 Deletion

You can request deletion of your account and personal information by contacting privacy@engx.com. Some information may be retained for legal or operational reasons.

6.4 Data Portability

You can request a copy of your data in a machine-readable format.

6.5 Opt-Out

You can opt out of marketing emails by clicking "unsubscribe" in any email or contacting support@engx.com.

6.6 Withdraw Consent

If we process your data based on consent, you may withdraw consent at any time.

6.7 Lodge a Complaint

You have the right to lodge a complaint with a data protection authority in your jurisdiction.

7. Data Security

We implement industry-standard security measures to protect your information, including:

Encryption of data in transit (TLS/SSL)
Encryption of sensitive data at rest
Secure password hashing
Regular security audits and monitoring
Access controls and authentication

However, no system is 100% secure. We cannot guarantee absolute security of your information.

8. Cookies and Tracking Technologies

8.1 Types of Cookies

EngX uses the following types of cookies:

Essential Cookies: Required for authentication and core functionality
Analytics Cookies: Track usage patterns and performance (Google Analytics)
Preference Cookies: Remember your settings (e.g., theme preference)

8.2 Cookie Control

You can control cookies through your browser settings. Disabling essential cookies may limit platform functionality.

9. Children's Privacy

EngX is not intended for users under 13 years of age. We do not knowingly collect personal information from children under 13. If we discover we have collected such information, we will delete it promptly.

Users aged 13-17 should obtain parental consent before using EngX.

10. International Users

EngX is operated in the United States. If you are located outside the U.S., your information may be transferred to and processed in the U.S. By using EngX, you consent to this transfer.

We comply with applicable data protection laws, including GDPR (for EU users) and CCPA (for California users).

11. AI and Machine Learning

11.1 AI Hint Generation

EngX uses OpenAI's API to generate personalized hints. Your problem context and optional answers are sent to OpenAI for processing. OpenAI retains this data for 30 days for abuse monitoring, then deletes it.

11.2 Learning from Interactions

We may use aggregated hint interactions (flagged hints, user feedback) to improve hint quality. Individual user data is not shared publicly.

11.3 No AI Training on User Data

Lynera does not use your personal data to train AI models, except for improving hint quality through aggregated, anonymized feedback.

12. Changes to This Privacy Policy

We may update this Privacy Policy from time to time. We will notify you of material changes by:

Posting an updated policy on EngX
Sending an email notification (if you have an account)

Continued use of EngX after changes constitutes acceptance of the updated policy.

13. Contact Us

If you have questions, concerns, or requests regarding this Privacy Policy, contact us at:

Privacy Inquiries: privacy@engx.com
Data Protection Officer: dataprotection@engx.com
General Support: support@engx.com
Parent Company: Lynera

14. Compliance

14.1 GDPR (General Data Protection Regulation)

For EU users, we comply with GDPR requirements, including:

Lawful basis for processing (consent, contract, legitimate interest)
Data minimization and purpose limitation
User rights (access, rectification, deletion, portability)
Data breach notification

14.2 CCPA (California Consumer Privacy Act)

For California residents, we comply with CCPA requirements, including:

Notice of data collection and use
Right to know, delete, and opt-out
No sale of personal information (we do not sell your data)

EngX is developed by Lynera