In this paper, we revisit the widely cited domain-specific software architecture (DSSA) for the domain of grid computing We have comprehensively studied 18 grid systems over the past five years, observing that, while individual grid systems are widely used and deemed successful, the grid DSSA is underspecified and makes it difficult to pinpoint what makes a software system a grid. Inspired by this conclusion, we describe our work-in-progress towards answering this important question.