Privacy Policy.

This Privacy Policy explains how victorhsn.com collects, uses and protects personal information when you visit this website or subscribe to the Engineering Playbook newsletter.

victorhsn.com is a personal publication about software engineering, artificial intelligence, computer vision and mathematics. It is designed to collect as little personal information as possible.

We aim to handle personal information transparently and responsibly, in line with applicable data protection laws, including the Brazilian General Data Protection Law (LGPD, Law No. 13,709/2018).

You can read this website without creating an account or providing personal information. We collect personal information only in the situations described below.

• Email address. When you subscribe to the Engineering Playbook, you provide your email address.
• Subscription and consent records. We record when you requested the subscription, the version of the consent text you accepted, where on the website you subscribed, the status of your subscription and when you confirmed or cancelled it.
• Confirmation data. To complete the double opt-in, we generate a single-use confirmation link. We store only an irreversible fingerprint (hash) of it, never the link itself.
• Analytics data, only with your consent. If you choose "Accept analytics", Google Analytics collects information about how you use the website, such as the pages you visit and how you arrived at them, general location (such as country or region) derived from your IP address, general device and browser information, and a random identifier stored in cookies on your device. Collection of more precise location and device details is disabled.
• Technical information for abuse prevention. When you submit the subscription form, your IP address is used to limit repeated requests. It is converted into a pseudonymous key before it is stored and is not used to identify you.
• Messages you send us. If you contact us by email, we receive your email address and the content of your message.

Like most websites, the infrastructure that delivers victorhsn.com may automatically process limited technical information, such as your IP address, browser type and the page requested, to deliver the website and protect it against abuse. We do not use this information to identify you or to build a profile about you.

We use personal information only for the following purposes:

• To manage your subscription to the Engineering Playbook, including confirming your consent through the double opt-in.
• To send you the newsletter, every two weeks, after you confirm your subscription.
• To respect your choice when you unsubscribe.
• To prevent spam, automated sign-ups and other abuse of the subscription service.
• To reply to messages you send us.
• With your consent, to understand how visitors use the website and improve its content.
• To measure overall website traffic and performance.
• To keep the website and its services secure and working properly.

We do not sell your personal information, use it for advertising or share it with third parties for their own marketing.

Under the LGPD, we rely on your consent to send the newsletter and to use Google Analytics. Other activities described in this policy, such as keeping the service secure and free from abuse, rely on the legal bases that apply to them.

The Engineering Playbook uses a double opt-in process, so no one can subscribe your email address without your confirmation:

1. You enter your email address in a subscription form on victorhsn.com.
2. We send a confirmation email to that address.
3. You confirm your subscription through the link in that email. The link expires after 48 hours.
4. After confirmation, you start receiving the Engineering Playbook.
5. You can unsubscribe at any time using the unsubscribe link included in the newsletter emails.

If a subscription is not confirmed, it is never activated and you will not receive the newsletter.

Subscription records are stored on Microsoft Azure, and emails are sent through Resend. When you unsubscribe, your email address is removed from our subscription records. We keep a minimal record, without your email address, for a limited period so that we can respect your choice and protect the service against abuse. See Data Retention for details.

We use a small number of service providers to operate the newsletter. They process personal information on our behalf and only for the purposes described in this policy.

• Resend. Sends confirmation emails and the newsletter and manages the list of subscribers, including unsubscribe requests. Data processed: email address and subscription status. Resend Privacy Policy.
• Microsoft Azure. Runs the subscription service and stores subscription records. Data processed: the information described in Information We Collect. Microsoft Privacy Statement.
• Google Analytics. Measures how the website is used, only after you choose "Accept analytics". Google signals and advertising features are disabled. Data processed: the analytics data described in Information We Collect. Google Privacy Policy.
• Cloudflare. Provides DNS and network services for victorhsn.com, routes subscription requests to our service provides Turnstile, a check that helps block automated sign-ups, and provides Web Analytics, which measures overall traffic and performance without using cookies. Data processed: IP address and technical information about your browser and device. Cloudflare Privacy Policy.

The website itself is delivered by a hosting provider, which may process the technical information described in Information We Collect.

victorhsn.com does not use advertising cookies. Optional analytics is used only with your consent.

If you choose "Accept analytics", we load Google Analytics, which uses cookies (such as _ga) to understand how visitors use the website and improve our content. If you choose "Reject optional", or until you make a choice, Google Analytics is not loaded.

Your analytics preference is stored for 365 days. After that, we will ask you to choose again. You can change your choice at any time through "Cookie Preferences" at the bottom of every page. If you withdraw your consent, Google Analytics stops collecting data from your visits, and we remove the analytics cookies that this website can access in your browser. You can also delete cookies at any time in your browser settings.

We also use Cloudflare Web Analytics to measure overall traffic and performance. It does not use cookies and does not depend on your analytics choice.

The subscription form uses Cloudflare Turnstile, which may process information about your browser and device to distinguish people from automated programs. It is used only for security.

If we introduce other non-essential cookies or analytics tools in the future, we will update this policy first and, where required, ask for your consent.

We keep personal information only for as long as necessary for the purposes described in this policy:

• Active subscriptions: while you remain subscribed.
• Unconfirmed subscription requests: deleted 30 days after the latest request.
• Confirmation links: deleted 7 days after they expire.
• Abuse prevention records: deleted automatically within a few days.
• Analytics data (Google Analytics): event-level and user-level data are kept for up to 14 months. Aggregated statistics in standard reports may be kept longer. This period is separate from your analytics preference, which is stored in your browser for 365 days.
• After you unsubscribe: your email address is removed from our subscription records. A minimal record, without your email address, is kept for up to 2 years and then deleted.
• Messages you send us: kept for as long as needed to respond and follow up.

Our service providers may keep certain information for longer when required by law or for their own security purposes, under their own privacy policies.

Under the LGPD and other applicable laws, you may have the right to:

• Confirm whether we process your personal information and access it.
• Correct incomplete, inaccurate or outdated information.
• Request the anonymization, blocking or deletion of unnecessary or excessive information.
• Request the deletion of information processed based on your consent.
• Receive information about the service providers with which your information is shared.
• Request the portability of your information, as provided by law.
• Withdraw your consent at any time, for example by unsubscribing from the newsletter or changing your Cookie Preferences.

To exercise these rights, contact us using the details in the Contact section. We may need to confirm that the request comes from the owner of the email address. You also have the right to file a complaint with the Brazilian National Data Protection Authority (ANPD).

We use reasonable technical and organizational measures to protect personal information, including:

• Encrypted connections (HTTPS) between your browser and our services.
• Access to subscription data limited to the systems that need it.
• Confirmation links that are random, single-use and time-limited, stored only as irreversible fingerprints.
• Protection against automated abuse, including bot checks and rate limits.
• Operational logs designed not to record email addresses, confirmation links or IP addresses.

No method of transmission or storage is completely secure, so we cannot guarantee absolute security. If we become aware of a security incident that affects your personal information, we will take appropriate steps, including notifying you and the authorities when required by law.

Our service providers may process and store personal information in countries other than Brazil, which may have different data protection laws. When this happens, we work with providers that commit to protecting personal information, and we take steps so that these transfers follow the requirements of the LGPD.

We may update this Privacy Policy to reflect changes to the website, the newsletter or applicable law. When we do, we will revise the "Last updated" date at the top of this page. If a change significantly affects how we use your personal information, we will highlight it on this page and, where appropriate, inform newsletter subscribers by email.

If you have questions about this Privacy Policy or want to exercise your privacy rights, contact us at [email protected].