With the growing complexity of knowledge production, social science must accelerate and open up to maintain explanatory power and responsiveness. This requires redesigning the front-end of research to build an open and expandable knowledge infrastructure that stimulates broad collaborations, enables breaking down inertia and path dependencies of conventional approaches, and boosts discovery and innovation. This article discusses the coordinated open-source model as a promising organisational scheme that can supplement conventional research infrastructure in certain areas. The model offers flexibility, decentralization, and community-based development and aligns with open science ideas, such as reproducibility and transparency. Similar solutions have been successfully applied in natural science, but social science lags behind. I present the model's design, and consider its potential and limitations (e.g., regarding development, sustainability and coordination). I also discuss open-source applications in various areas, including the first open-source survey harmonization project in social science
