A Google Go developer uses the Go programming language, also known as Golang, developed by Google to build efficient, reliable, and easy-to-understand software. They design and develop high-performing systems, write clean and testable code, debug programs, and integrate applications with various third-party web services. They also engage in system analysis, code reviews, and respond to feedback to improve the functionality of their applications. Additionally, they collaborate with other team members, participate in architectural decision-making, and stay updated with emerging technologies to ensure the software they create meets the highest standards.