How do you let people share a result publicly without exposing anything private?

I’m building an app solo, and users can share their results as a link. The page has to open for people who aren’t logged in, but the data belongs to a private account.

What I did: the link uses a random code instead of the real ID, and the page only gets the few fields meant to be public. Then I tested it in a private window, with a real code and a fake one.

It works, but I’m not sure it’s enough. If you’ve built something like this, what do you wish you’d checked earlier?