San Francisco often has higher nominal salaries for software engineers with your experience level. However, consider the real difference after accounting for rent, taxes (state and local), and everyday expenses. While SF might offer, say, 15-20% more on paper, your disposable income might not be that much higher, or even lower, due to the extreme cost of housing. Seattle has been catching up salary-wise, so run a detailed cost-of-living comparison for your specific situation.