The growing complexity of modern software systems, driven by larger codebases and evolving technologies, has amplified the need for effective collaboration in developer teams. Specifically, in open-source software (OSS) projects, where contributors often vary in background and engagement in the process, this complexity may introduce further collaborative challenges. As projects scale, coordination becomes increasingly difficult to maintain, highlighting the importance of understanding the socio-technical dynamics of effective development. While prior research emphasizes the role of collaboration, its influence on software delivery remains underexplored. In order to address the gap, this study examines how team characteristics, such as size and expertise, and communication practices, like interactions on issues and pull requests, relate to delivery efficiency in OSS projects. Based on an empirical analysis of 887 GitHub repositories, we found that team size and project expertise exhibit the strongest relationships with delivery size and frequency. Core contributor activity also shows positive but diminishing effects over time, while communication practices demonstrate no noticeable associations with release efficiency. These findings suggest that optimizing delivery in OSS projects may benefit from considering adaptive team structures and aligning CI/CD practices with the project stage and the evolving dynamics of the developer team.