Understanding the software development practices of blockchain projects: a survey

Background: The application of the blockchain technology has shown promises in various areas, such as smart-contracts, Internet of Things, land registry management, identity management, etc. Although Github currently hosts more than three thousand active blockchain software (BCS) projects, a few software engineering research has been conducted on their software engineering practices. Aims: To bridge this gap, we aim to carry out the first formal survey to explore the software engineering practices including requirement analysis, task assignment, testing, and verification of blockchain software projects. Method: We sent an online survey to 1,604 active BCS developers identified via mining the Github repositories of 145 popular BCS projects. The survey received 156 responses that met our criteria for analysis. Results: We found that code review and unit testing are the two most effective software development practices among BCS developers. The results suggest that the requirements of BCS projects are mostly identified and selected by community discussion and project owners which is different from requirement collection of general OSS projects. The results also reveal that the development tasks in BCS projects are primarily assigned on voluntary basis, which is the usual task assignment practice for OSS projects. Conclusions: Our findings indicate that standard software engineering methods including testing and security best practices need to be adapted with more seriousness to address unique characteristics of blockchain and mitigate potential threats.