As regards to France (not sure how this varies from country to country, even the EU) it's fairly easy to get a visa (as in conditions), but the issue is that you'll have to renew it every year which is a fairly tedious process and has to be done in-person.

A few years back I used to have an American friend who got here on a student visa and later changed to a regular one when she started working. Granted, she wasn't in tech or anything like it, but she always had a steady long term work contract. They never wanted to give her a long-term visa for some reason. It's one of the reasons she went back to the US.