Worked extensively across the full stack, with an emphasis on the core blockchain protocol implementation: the consensus and fault algorithms, networking code, API layers, and command-line tools and test suites. I fixed, improved, built, deployed, and maintained applications and products beyond the core protocol, including: official websites and web services; wallet and blockchain explorer software and libraries; external data and service integration; and both open source and proprietary product design, specification, and development for clients and demonstrations. I'm worked closely with the QA and testing specialists to ensure product integrity.