Privacy notice
Last updated 30 October 2026
Klangfarbe is built by su.engineering. This notice covers klangfarbe.su.engineering and the request form on it. It describes the site as it stands today, not a product that has shipped.
What we collect
What you type into the request form: your work email address, your organization, the perspective you would review from, and what you asked for.
We count visits with Umami, which we run ourselves on our own server and serve from analytics.su.engineering. It records the page visited, the referring site, coarse signals like country, browser and screen size, and which buttons are used, such as the demo scenarios. It sets no cookies, stores no IP addresses, assigns you no identifier and does not follow you to other sites. When you send the form it records only that a request was sent and the perspective you chose, never your address or organization.
There is no advertising and no tracking pixel, and we set no cookies of our own.
Why we collect it
To answer your request: send the whitepaper, arrange a review conversation or discuss a proof of concept. We do not sell, rent or share this information, and we do not use it for anything beyond your request. The lawful basis is our legitimate interest in responding to a request you made of us.
Who processes it
- Resend delivers the two emails a request produces: the request itself to our internal address, and your confirmation copy. Your submission passes through Resend and is stored in its delivery logs.
- Cloudflare Turnstile checks that the form was submitted by a person rather than a bot. It may set a short-lived cookie to remember that the check passed, and it sees your IP address in order to do its job. We never receive that IP address.
- Umami is the visit counter above. It runs on our own server, so no analytics company receives anything about your visit.
- Our hosting runs the site on a server in Europe. Standard web server logs are kept for operational purposes.
How long we keep it
Requests live in our mailbox for as long as the conversation they start is useful, and no longer than 24 months. If you ask us to delete yours sooner, we do it, and nothing survives beyond what our email provider holds in its own logs.
Your rights
If you are in the EU or the UK, you can ask for a copy of what we hold, ask us to correct it, ask us to delete it, or object to our holding it at all. Write to hello@su.engineering and we will answer. You may also complain to your national data protection authority.
Changes
When this notice changes, the date at the top changes with it. If a change affects people who have already written to us, we tell them.