You won’t be taxed by the Finns since you need to be there 181 days to be considered a tax resident. For those staying for about a year, the US has a FEIE exemp

You won’t be taxed by the Finns since you need to be there 181 days to be considered a tax resident. For those staying for about a year, the US has a FEIE exemption that kicks in for the first 105k or so anyway. No exception for California taxes, however.