Almost every state considers any income for work done while you are physically within the state as income sourced from the state. This means you pay taxes whether you are a resident or not. Most states have some sort of threshold, either number of days or earned income. For tech workers you are likely to hit earned income thresholds pretty much instantly as it is usually prorated according to the number of days you are in the state. That said, a huge number of people just commit tax fraud by never paying or filing. Mostly only CA and NY spend any significant resources identifying and pursuing these people.