A Geb developer specializes in the Geb testing framework, built on top of Selenium, Groovy language, and Spock testing framework. They design, code, and implement automated tests for web applications, ensuring they function as expected. Their responsibilities involve creating test scripts, identifying and fixing bugs, and improving testing processes. They utilize Geb's advanced features like page object model for structuring tests in a reusable and readable way. They often collaborate with other developers and stakeholders, providing feedback and recommending changes. Furthermore, they maintain documentation to ensure efficient workflow and future reference. Their ultimate goal is to enhance the software's reliability and performance.