Initially designed as decentralized ledgers for cryptocurrencies, blockchains have evolved to support digital transactions in financial services, healthcare platforms, governments, and various supply chains. Unfortunately, due to their inherent complexity, theoretically fault-tolerant blockchain transactions have been shown to be vulnerable in practice as they are prone to data loss. This project aims to bridge the gap between blockchain theory and practice. The project’s novelties are holistic coverage of the entire blockchain ecosystem to (1) capture their inherent dependencies; (2) identify their critical transaction states; and (3) ensure their effectiveness and efficiency thorough testing and measurement. The project's broader significance and importance are fundamentally advancing the fault tolerance of decentralized transactions, thus benefiting all sectors in modern society that need to maintain and exchange digital data.<br/><br/>This project focuses on the heterogeneity of computing, storing, and handling network resources in the blockchain ecosystem to lay a solid foundation for blockchain fault characterization and system construction. The project derives dependency-aware configuration models and prioritization algorithms to guide state exploration and conducts principled scheduling with multidimensional complementary metrics for scrutinizing the fault tolerance properties of transactions systematically and automatically. In doing so, the project advances the rigor of blockchain research and increases the confidence in blockchain technology adoption in the real world. The key ideas spanning the blockchain ecosystem stimulate research and education innovations in closely related fields (e.g., distributed systems, operating systems, storage systems, cloud computing, software engineering, and disaster response) and benefit a wide range of practitioners and applications relying on these relevant technologies. In addition, the holistic innovations are naturally aligned with other large-scale infrastructures for ensuring the robustness of mission-critical systems and the integrity of digital data in general.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.