The recent years have witnessed an increasing interest by researchers to explain and build models of bottom-up open collaboration (e.g., open source software development, Wikipedia), using theories and tools borrowed from complex systems science, such as self-organization, critical cascades, and complex networks. As research in nature and society gets increasingly driven by data and computation, the “data science way” has emerged as a powerful leverage to, on the one hand, help researchers keep better account of their collaborative work in a transparent way and, on the other hand, to reach out and engage with a larger community of researchers and science enthusiasts, ready to help, driven by intrinsic motivation and fun. Furthermore, the “data science way”, is also deeply associated with the emergence of collective intelligence through social interactions and physical meetings where people do stuff together (e.g., hackathons). Unfortunately, the structure and the dynamics of these punctual meetings have not yet been completely understood.