Sr AI Research Scientist, AI Evaluation and Reliability at Upwork

This role is designed for an expert-level AI Researcher who specializes in making Large Language Models (LLMs) and generative systems more dependable. You should have a strong background in deep learning, specifically focusing on uncertainty estimation, hallucination detection, and evaluation frameworks for agentic architectures. This is an applied research position, meaning you must be comfortable bridging the gap between scientific discovery and production-ready code. A major highlight of this position is the opportunity to work on "Uma," a flagship AI model operating at a massive marketplace scale. You will have a high degree of technical autonomy to shape the company’s AI research strategy and will be encouraged to contribute to the external research community through publications. Note that this role is based on-site in Toronto and will initially be managed through a hiring partner while the local hub is established. **You might be a good fit if you...** * Have a track record of improving the reliability and "trustworthiness" of AI systems in real-world applications. * Are highly proficient in Python and PyTorch and can navigate complex, retrieval-based workflows. * Enjoy mentoring other researchers and collaborating cross-functionally with product and engineering teams. * Thrive in a "bottom-up" environment where you are expected to frame your own research hypotheses and see them through to deployment.