Co-owned two React + TypeScript web apps (Vite; GraphQL; RTK Query; Ant Design; Tailwind), implementing core flows and integrating backend APIs. Shipped Project A (20 routes, 8 modules, 91 acceptance criteria) and Project B (15 modules, 19 routes, 145 merges / 661 commits); ensured release readiness via internal reviews. Built han-agents, a generative-AI multi-agent that generates and refines unit tests; deployed to 4 production projects, reducing test creation from weeks to ~1 day. Piloted an AI-enhanced Jira workflow and authored internal AI SOPs.