253
The CEO of Dropbox has a 90/10 rule for remote work
(www.businessinsider.com)
This is a most excellent place for technology news and articles.
Employees usually have to be a tax resident in the country they are working for in Europe. Depending on the country you can go as a contractor. That can also be tricky as some countries have rules against freelance contractors only working for one client - to get around companies having employees but not registering them as employees and giving them full employment rights and benefits.