Information System Development (ISD) relies on cross-functional teams with distinct cultures and nonoverlapping knowledge. Developing a shared understanding of the business needs and associated IS solutions by drawing upon these disparate knowledge sets is critical for project success. We adopt a “practice” view of system development, which emphasizes the relevance of knowledge boundaries between different communities in a system development process. We extend this perspective by testing the impact of different forms of boundary-spanning competencies and practices on ISD success. By analyzing 136 ISD projects in a global US automotive OEM, we show that the presence of boundary spanning roles, acculturative processes, and cross-domain knowledge and experience acquisition are significant factors positively affecting IS development success. We also demonstrate that facilitative boundary spanning roles - ambassador, coordinator, and scout - moderate the relationship between accumulated IS business domain knowledge and ISD success and that IS business competence is determined by acculturation among IS teams, and the technical competence of the IS team. This suggests that IS teams with low levels of business domain knowledge may be able to mitigate this deficit by exhibiting boundary spanning behaviors to enhance the flow of information across the knowledge boundaries.