Among numerous reasons for software project failure, coordination failure is considered as especially salient. Prior studies on coordination in software development are confined to team internal coordination and do not explicitly differentiate team internal and external coordination processes. This study proposes a research model to explain the antecedents of coordination effectiveness of software developer dyads from interacting teams. We explore the antecedents by integrating inter-personal coordination and technology-based coordination. Data were collected from 59 software developer dyads from different interacting teams as well as software developers’ managers. The results reveal that implicit knowledge sharing has a significant positive impact on coordination effectiveness. Social capital (mutual trust and project commitment) has a significant impact on knowledge sharing with mutual trust directly affecting both implicit and explicit knowledge sharing. Project commitment also has a direct impact on explicit knowledge sharing and mutual trust, but it does not directly affect implicit knowledge sharing.