Evolving Competencies in Blockchain Engineering: A Longitudinal Replication Study

Abstract

We report a five-year, construct-preserving longitudinal replication of a 2020 empirical study of blockchain-engineer job advertisements, extended to a global 2025 cohort. Using mixed text-mining and expert-validated coding grounded in established competency taxonomies, we analyze 235 postings from 31 countries to examine how blockchain-specific, general technical, and soft-skill demands have evolved under an aligned measurement protocol. The findings indicate professional maturation from single-platform prototyping toward multi-chain, production-grade engineering that integrates back-end development, deployment operations, and security. Ethereum remains the most frequently cited platform, while Solana and other ecosystems increase platform diversity. Smart-contract development becomes a baseline expectation, with Solidity remaining central and Rust and Move becoming mainstream. Operational tooling such as cloud and containerization, alongside security-oriented practices including audits and zero-knowledge proofs, appears as recurring demand signals. Soft-skill mentions rise substantially, while formal degree requirements decline in favor of experience-based qualification. We contribute an updated 2025 competency atlas and empirically grounded implications for software engineering research, hiring, and curriculum design, while acknowledging comparability limits inherent to global sampling and cross-period labor-market conditions.