Dražen Popović contributed to the IntersectMBO/ouroboros-consensus and IntersectMBO/cardano-node repositories, focusing on security documentation and build stability. He updated the SECURITY.md file to accurately reflect project specifics and vulnerability reporting, improving audit readiness and security governance using Markdown and Haskell. In the Cardano node repository, Dražen stabilized build and dependency configurations by updating cabal.project index-state and CHaP flake inputs, which enhanced CI reliability and reproducibility. His work demonstrated a disciplined approach to documentation, package management, and DevOps, addressing both process and technical challenges to support secure, maintainable, and reliable blockchain development within a short engagement period.