Okay, let’s tackle this. So Graham has 27 years of experience as a Senior Software Engineer, which is a long time and indicates high expertise. The fact that he’s still working at the same company after 27 years also suggests he’s doing something right. His Master’s degree in Mathematics from Cambridge adds significant value. Software engineers with his level of experience and education typically charge higher rates. Considering the location is Miranda, California, which is in the tech hub of the US, and the industry demand for skilled software engineers, I’d estimate his hourly rate to be around $200. This is slightly lower than what top software engineers in similar positions might charge, but still reflects his significant experience and education.