Sr Lead AI Research Scientist, AI Foundations at Upwork

This role is designed for an elite AI researcher with a PhD and a strong track record of publishing at top-tier conferences (NeurIPS, ICML, ICLR). You should be a technical leader who thrives in a "startup-style" environment, capable of taking high-level research concepts from ideation through to production-grade deployment. Expertise in LLMs, Generative AI, and reliability (mitigating hallucinations) is essential. You will be a founding member of the new international operational hub in Lisbon, Portugal. This is a high-impact leadership position where you will advise the executive team on AI strategy and mentor junior scientists. While the role is initially managed through a hiring partner as the hub is established, it offers a unique opportunity to shape the AI foundations of a major global marketplace from the ground up. **You might be a good fit if you:** * Hold a PhD in a relevant field and have extensive industry experience in machine learning. * Have multiple first-author publications at prestigious AI conferences. * Are proficient in Python and PyTorch and can bridge the gap between academic research and scalable production code. * Want to lead research on agentic systems, reinforcement learning, and AI-human collaboration.