airCFO is an AI-powered accounting & finance services partner to 300+ startups (current/former clients include Anthropic, Replit, Harmonic), and we are building a platform to supercharge our service's capabilities. We're hiring a founding engineer to build the systems behind it: a retrieval/RAG context layer over all our tools, and the internal apps (TypeScript, Node, Python/FastAPI, React, Postgres, Claude + MCP) our teams use daily. We want someone senior who drives coding agents hard but refuses to lose the plot — clean architecture and a real mental model of the whole system. Production RAG/agents a plus, not a requirement. You'd report to a hands-on fractional CTO; small team, high autonomy. Email me at yair [dot] aviner {at} aircfo.com with "HN - Founding Engineer" in the subject.