What are some conventions (in the likes of ComicCon) for techies/nerds, computer/data folks? Maybe one that occurs in many cities, like ComicCon

Say you like programming or computers or Linux or data (SQL R Python PowerBI, whatever) or web or game development or even music/video editing? What are some of the conventions other than ComicCon that could be interesting?

Looking for any major events like ComicCon... if there are any

For example in the screenshot (twitch clip), if you want to share on reddit you click the reddit button, but what button are devs supposed to put to share in the fediverse? Do they pick an instance of their choice?! Is this a weakness of a federated platform or what?

Whenever I try to install the app on Chrome on my Android phone I get a generic "impossible to install / an error has occurred", with no more info. Any idea what's the problem? I have other web apps installed just fine.

On my desktop (Chrome, Windows) I appear logged out and I can't log in--when I click on log in and enter user& pass it says I've connected successfully, but nothing happens (I still appear logged out, can't comment, can't post, etc.). However, when I go to a page I've already been to (like my user page), then I "become" logged in (without having to log in), and when I go back to the home page I'm suddenly logged in.

On my phone (Chrome, Android) I don't have this problem. What to do? Clearing cache doesn't work, I've done it many times now.