What we collect, in full

We use PostHog on its EU infrastructure, in cookieless mode. Nothing is stored on your device: instead of a cookie or a device id, PostHog derives a short-lived identifier from your IP address and browser string that rotates daily, which is enough to count a visit and not enough to follow you tomorrow or anywhere else.

What that records: which pages are viewed, the referring site, an approximate country derived from the IP address, and clicks on outbound links to organisers — the last one is how we can tell an organiser how much traffic we sent them. Session recording, autocapture and surveys are switched off.

Analytics requests go through hackalendar.com and are forwarded server-side, so your browser never connects to a third-party analytics host. There is no consent banner because there is nothing to consent to: this is audience measurement without cookies or cross-site tracking, which we assess as exempt under the CNIL’s audience-measurement guidance. That self-assessment is written down and kept on file.

When a page breaks, Sentry receives a technical report: the stack trace, the URL, and browser and OS versions, along with the IP address the failing request came from. It is used to fix the bug and nothing else. We do not attach the contents of anything you typed.

If you subscribe, we store the email address you give us and the record of your confirmation, with Brevo, on EU infrastructure. It is double opt-in: you get one confirmation email and receive nothing else until you click the link in it.

There is no open-tracking pixel — we do not measure whether you opened an email. Every email has a one-click unsubscribe, and if you would rather be erased outright than marked unsubscribed, ask and we will delete the address. We never pass it to anyone.

Event facts: names, dates, venues, links, and the public name and page of the organising company or community. We do not collect organiser email addresses or personal contact details, and we publish this on a legitimate-interest basis — it is public information about public events, and we send traffic back to the source.

If you are an organiser and want a listing or a logo removed, write to hello@hackalendar.com and it is done — no forms, no argument.

Vercel hosts the site, Neon stores the database, PostHog (EU) handles analytics, Sentry handles error reports, and Brevo handles the newsletter. Each acts only on our instructions, under its own data processing agreement. There is no one else.

No advertising, no ad networks, no third-party trackers, no social media pixels, no fingerprinting, no profiles, no selling or sharing your data with anyone for marketing. There are no accounts, so there is nothing to log into and no password to lose.

Under the GDPR you can ask what we hold about you, have it corrected or deleted, object to how we use it, or ask for a copy. Write to hello@hackalendar.com and we will answer within a month. If our answer does not satisfy you, you can complain to the CNIL, the French data protection authority.

How the listings themselves are sourced and checked is on the how we curate page.