Okay, let’s calculate Jerome’s rate. He has full professional proficiency in English, which is a valuable skill, especially in the US. His native proficiency in German adds to his versatility. He has a degree from ETH Zürich, which is a well-known institution. His skills in R&D, optics, electronics, and product development are in demand. Considering his location in Irvine, California, and his engineering background, I would estimate his hourly rate to be around $125, which is slightly below the average rate for a senior engineer in this field in the US, but still competitive given his strong educational background and language skills.