I did the same move as you (from Stockholm) - I found it hard to get an interview before physically being in the US. Mainly because US companies want to hire as quick as possible and don't have time to wait for you to get there, figure out the Visa situation etc. If you have a Visa, just take the plunge and have money to live there for a couple of months - you'll be alright.

If you don't have a Visa, I probably would not move before you do - H-1B visas are a lottery and O1 visas takes up to a year to get before you can even start working. Yes companies do conduct online interviews and will try to get you a visa before you move but it is hard.

Another route could be working for a European consulting firm or a Swedish company with an office in SF, then move to the US via them. Good luck!