Amid the rise of computational and data-driven forms of journalism, it is important to consider the institutions, interactions, and processes that aim to help the social worlds of journalism and technology come together and collaborate around a common cause of news innovation. This paper examines one of the most prominent such efforts: the transnational grassroots organization called Hacks/Hackers. Through a two-year qualitative case study, we sought to understand just how journalists and technologists would engage through this organization: what kinds of interactions would occur, and what factors might facilitate collaboration? Drawing upon the science and technology studies concept of "trading zones," we examine how Hacks/Hackers functions as an informal and transitory trading zone through which journalists and technologists can casually meet and coordinate. The level of engagement between the two groups, we found, depends on a set of social and structural factors, including institutional support and the leadership of key volunteers, and the depth of that engagement depends on sufficient mutual understanding among journalists and hackers. We discuss the implications of these findings for understanding the challenges and opportunities presented through the intersection of journalism and technology.