I was connected to the uni’s wifi, which I access with my institutional account, on my personal laptop. If using the app Notion - accessed with my personal gmail account - and writing on it, what can they see? do they have access to what I’m writing? Do they just see I’m using it?
Short version: No, most likely not.
They see who you are, but not what you do.
Slightly longer: Someone can probably see your connections to google and notion and infer that you are using Notion, but they cannot see your Google/Notion account and not what content you are working on. (Also those are very popular tools, unless you are the enemy of the state number 1, why would they care?)
Even longer: If your laptop or your gmail or your notion account is compromised, they can see everything.
Compromised…? 😨 What do you mean
If your Web browser or OS accepts a CA issued by the school.
But how to check that
Navigate to notion.com. check the certificate. (Click on of the icons in the browser bar on the left). Remember what you see (take a screenshot)
Do the same in a different Wifi network.
If the certificate differs, this is highly suspicious.