Senior AI Engineer

Re:Build Manufacturing is building Reflow, an AI-powered platform for hardware product development. This senior role is focused on designing and building LLM-powered agents that coordinate cross-disciplinary engineering workflows, surface risks, and generate structured deliverables. You will own the agent orchestration layer (currently LangChain DeepAgent) and contribute to architecture decisions across the stack. This is a remote-first US-based role with preference for candidates near Re:Build offices in Boston, Seattle, or Los Angeles.

• Design, build, and iterate on LLM-powered agents that coordinate across engineering disciplines, surface project risks, and generate structured deliverables (proposals, SOWs, status reports).
• Own the agent orchestration layer (currently LangChain DeepAgent) and continuously evaluate whether to extend, replace, or supplement it.
• Implement robust tool-use patterns connecting agents to external systems (project management tools, CAD/PLM platforms, communication channels) via APIs and integrations.
• Design and tune prompts, chains, and retrieval strategies to maximize agent reliability, accuracy, and usefulness.
• Build evaluation and observability infrastructure for agent performance, including tracing, cost tracking, latency monitoring, and automated quality benchmarks.
• Develop streaming agent interfaces that surface real-time progress, reasoning transparency, and proactive alerts.
• Collaborate with frontend and backend engineers on UX, data pipelines, and API design; contribute to architecture decisions and code reviews.