Sr. Software Engineer, Agents

Sourced from jobs.ashbyhq.com

Plug, an AI-native marketplace for used electric vehicles, is hiring a Senior Software Engineer to build production LLM agents and multi-agent workflows. You'll turn operational problems like document extraction, title review, and dealer communication into reliable agents, and ship full-stack tooling where people review agent output. The role is onsite in Sawtelle (between Santa Monica and West LA).

• Build and ship agents and multi-agent workflows for operations, dealers, and sellers
• Use LangChain and LangGraph to build agents, and LangSmith or Langfuse to trace, debug, and evaluate them
• Write evals, build datasets from real cases, and measure accuracy and failure modes
• Integrate agents with existing services through clean APIs and tools
• Monitor agents in production for cost, latency, error rates, and human-review rates
• Ship full-stack TypeScript and React screens plus backend endpoints
• Help the rest of engineering adopt agent patterns with reusable tools and write-ups

• 5+ years of full-time industry software engineering with production shipping experience
• Strong TypeScript or Python and comfort across APIs, databases, and frontend
• Hands-on experience building LLM features in production: tool use, retrieval, structured output, and evaluation
• Experience with an agent framework and observability stack, ideally LangChain, LangGraph, LangSmith, or Langfuse
• Agent-first mindset with self-built tooling such as skills, MCP servers, custom workflows, or evals
• Comfort building inside systems designed by others and strong written communication
• BS in computer science or related field, or equivalent experience

• Experience with document-heavy workflows such as titles, registrations, inspections, lending, or insurance
• Experience with vehicle, marketplace, or auction products
• Experience with human-in-the-loop review tools or fine-tuning and prompt optimization for production LLM features