Jonathan James Castillo

Today

I'm currently at TeamUp, designing an app that helps people connect and play sports — a Tuesday-night pickup or something with a little more on the line. I've spent 6+ years across research, flows, and polished UI in Figma, previously leading design for a top-11 U.S. homebuilder, Workday-partner migration tools, and a real-estate platform that scaled to 70K+ users. I work design-through-code with Claude Code, MCP tools, and modern workflows so prototype and production feel like one continuous thought, not a handoff.