Background: Software development teams are increasingly diverse, embedded, and cross-disciplinary. Domain experts (DEs) from different disciplines collaborate with professional software developers (SDEs), bringing complementary expertise in creating and maintaining complex production software. However, contested expectations, divergent problem-solving perspectives, and conflicting priorities lead to friction. Aims: This study aims to investigate the dynamics of emerging collaboration of cross-disciplinary software development (CDSD) by exploring the expectations held by DEs and SDEs and understanding how these frictions manifest in practice. Method: We utilize Activity Theory (AT), a well-established socio-technical framework, as an analytical lens in a grounded, empirical investigation, conducted through a mixed-method study involving 24 interviews (12 DEs and 12 SDEs) and a large-scale validation survey with 293 participants (161 DEs and 132 SDEs). Results: We conceptualize and empirically ground the CDSD dynamics. We identified eight expectations held by SDEs and six by DEs. By mapping these expectations to AT components, we revealed 21 frictions in CDSD and illustrated where and how they arise. Conclusions: This study offers a theoretical lens for understanding the dynamics and frictions in CDSD and provides actionable insights for future research, practitioners, and infrastructure design.

翻译：背景：软件开发团队日益呈现多元化、嵌入式与跨学科特征。来自不同领域的领域专家（DEs）与专业软件开发人员（SDEs）开展协作，在创建和维护复杂生产软件过程中带来互补的专业知识。然而，相互冲突的期望、差异化的解决问题视角以及矛盾的优先级导致了协作摩擦。目标：本研究旨在通过探究DEs与SDEs持有的期望，并理解这些摩擦在实践中如何显现，从而深入探讨跨学科软件开发（CDSD）中新兴协作的动态机制。方法：我们采用成熟的社会技术框架——活动理论（AT）作为分析视角，开展了一项扎根式的实证研究。该研究采用混合方法，包含对24名参与者（12名DEs与12名SDEs）的访谈，以及对293名参与者（161名DEs与132名SDEs）的大规模验证性问卷调查。结果：我们对CDSD动态机制进行了概念化与实证奠基。我们识别出SDEs持有的八项期望与DEs持有的六项期望。通过将这些期望映射至AT组件，我们揭示了CDSD中存在的21种摩擦，并阐明了其产生的位置与方式。结论：本研究为理解CDSD中的动态机制与摩擦提供了理论视角，并为未来研究、实践者及基础设施设计提供了可操作的见解。