Privacy Policy

This policy explains what information lean4.dev may collect, how it is used, and how advertising works on the site.

Last updated: September 12, 2026

Who operates this site

Lean 4 Dev is an independent educational website available at lean4.dev. For privacy questions, contact contact@lean4.dev.

Information you provide

If you email the site, the message may include your email address, name, and any information you choose to include. This information is used to respond to your message, handle corrections, and improve the site.

Forum contributions and guest cookie

The forum stores the display name, text, category, related story, and timestamps you submit. Published topics and replies are visible to other visitors. Display names are unverified; an email address or account is not required. Do not include private information in a post.

A signed, HTTP-only cookie named lean4_forum_guest identifies your browser so you can remove your own posts and so the forum can limit repeated submissions. It lasts up to one year and is renewed when you use the forum. Clearing it removes your ability to manage earlier posts from that browser.

Reports and their reasons are available to moderators. Removed posts are hidden from public view but remain in the database for moderation. Contact the site if you need permanent deletion or have lost access to a post. Rate-limit records use guest identifiers and, when trusted proxy support is enabled, a keyed hash of the network address. Records older than two minutes are cleared on subsequent successful forum writes.

Academy accounts, learning, and payments

Academy accounts use Google Firebase Authentication. We store your account identifier, email address, subscription status, completed exercise identifiers, and compiler usage counters to provide access, save progress, and enforce published allowances. Authentication data is processed by Google; passwords are not stored by the website application.

Stripe processes subscription payments, billing details, invoices, and cancellation requests. We store Stripe customer and subscription identifiers and access dates. Payment card numbers are entered on Stripe’s hosted checkout and are not stored by this website.

When you check code, the submitted source is sent to an isolated compiler on Google Cloud. The compiler does not intentionally log source code, and its temporary execution files are discarded after each run. Code drafts are saved in your browser’s local storage. Hosting services may retain operational request logs. Do not submit passwords, API keys, or confidential data as code.

Account and progress records are retained while needed to provide the service. To request access to or deletion of account data, contact contact@lean4.dev. Billing records may need to be retained separately to meet applicable recordkeeping requirements. Cancel a paid subscription through My account before requesting account deletion.

Automatically collected information

The hosting provider and security services may process standard technical data such as IP address, request URL, browser type, device information, referrer, and timestamps to deliver the site, prevent abuse, and troubleshoot errors.

Cookies and advertising

This site may use Google AdSense. When ads are enabled, Google and its partners may use cookies or similar technologies to serve ads, limit repeat ads, measure ad performance, and help prevent fraud.

Learn how Google uses data on partner sites at policies.google.com/technologies/partner-sites.
Manage Google ad personalization at adssettings.google.com.

EEA, UK, and Switzerland consent

For visitors in the European Economic Area, the United Kingdom, and Switzerland, personalized advertising should only be served after the required consent has been collected through a Google-certified consent management platform where required by Google policy and applicable law.

Data sharing

Lean 4 Dev does not sell personal information. Data may be processed by service providers that help operate the website, deliver security, handle email, or provide advertising and measurement services.

Your choices

You can block or delete cookies in your browser settings.
You can opt out of personalized Google ads through Google ad settings.
You can contact the site to request deletion of email correspondence you sent.

Changes

This privacy policy may be updated when the site changes providers, analytics, advertising setup, or contact workflows. Material changes will be reflected on this page.