Gilfoyle is a software designer, and a main character in HBO's Silicon Valley. Gilfoyle lives and works in the Hacker Hostel with Richard, Big Head, and Dinesh. He is pompous and purports to be good at system architecture, networking, and security. Gilfoyle often finds himself sparring with Dinesh about things such as their work efficiency, Dinesh's Pakistani ethnicity, Gilfoyle's religion along with other negligible matters. He is a self-described LaVeyan Satanist, and bears an upside-down cross tattoo on his right arm.