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