I use Sanity.io as CMS here. While generally irrelevant, all images you see here are served to you from Sanity CDN. Sanity does not preserve logs of how you access these images and does not introduce any kind of tracking or data collection. Sanity is also pretty awesome ;)
Auth0 provides user authentication functionality. Stores email, password (if any), user_id (social or auth0-specific), logins count, exact IP, approximate location (country, region, city), exact time of the last login, user gravatar (based on email or social account), user agent. Passwords are stored hashed and salted, and I don’t have access to them, not even in this hashed/salted form. There is a way to officially request user export from Auth0 that includes hashed/salted passwords, but it’s a severely regulated process. Some of the login event information is also stored in Auth0 logs for 30 days. Let me know if you want to learn more, I know a lot about how Auth0 handles this sort of data :)
As a newsletter service, I’m using Buttondown.email. There is no tracking aside from UTM in URLs. Email addresses are stored in the service in plain text, along with the source tag (where did the subscriber find the link). Opens and clicks are not tracked.
For transactional emails (comments notifications) I use Mailgun. There is no tracking of any kind, however, the service requires that I pass your email address (the one you use as a login here). This email address is not stored anywhere aside from a 5-day Mailgun log, and as soon as the email notification is sent and 5 days have passed, Mailgun has no memory of it whatsoever.
As of May 2022, I use Supabase to store comments. There are a few tables there, and for every comment, I store your Auth0 profile (the one you use to log in), the content of the comment, and metadata (timestamp, flags, what post it belongs to).
To the best of my knowledge, there are no other services or features where I would come across any information that could possibly identify you personally or allow me or anyone else to track you or your activity on this website.
If you want me to make sure that there’s no information specific to you stored in any of the systems mentioned above, just let me know.