Senior Lead Machine Learning Engineer, Agentic AI at Upwork

This role is designed for an expert Machine Learning Engineer who has moved beyond basic LLM implementation into the world of **Agentic AI**. You are the ideal candidate if you have a deep background in building autonomous multi-agent systems—handling complex tasks like chain-of-thought reasoning, tool-use, and self-reflection—and can bridge the gap between applied research and production-grade backend engineering. The standout feature of this position is the opportunity to define the "Agentic Platform" for a global talent marketplace. You’ll be architecting the core infrastructure (APIs, SDKs, and orchestration services) that both internal teams and external developers will use. While the role is currently managed through a local partner in Toronto, it offers the high-impact environment of a Nasdaq-listed tech leader transitioning into an AI-first era. **You might be a good fit if you...** * Have successfully shipped LLM-powered agents with sophisticated task-planning and "human-in-the-loop" capabilities to production. * Are proficient in **Python** and distributed systems, with the ability to tune models (SFT, DPO, RLHF) specifically for agentic workflows. * Can build rigorous evaluation frameworks to measure success rates, hallucinations, and latency in non-deterministic systems. * Enjoy mentoring senior engineers and influencing technical roadmaps across a large organization.