This study aims to investigate how collaboration occurs in decentralized open-source communities and the underlying dynamics that shape collective problem-solving. Drawing on collective intelligence literature and using data from 10 of Ethereum’s GitHub repositories, our main results show the duality of promise and challenge in decentralized collaboration. On the one hand, Ethereum demonstrates structured coordination with activity peaks at issue creation and resolution; on the other hand, it faces structural barriers, including knowledge silos, high turnover, and reliance on a small group of contributors. Our study contributes to the discussions on decentralized collaboration and collective intelligence, offering novel insights into blockchain platforms.