Member of Technical Staff - Research, Post-Training

About Us: AI needs a new infrastructure layer. We're building it at Modal. Every era of computing brought new workloads that previous infrastructure couldn't support: mainframes, databases, and the cloud. Each time, the company that rebuilt the layer underneath defined the decade. AI is no different, except it touches everything instead of one slice, and the window to build the layer underneath it is open right now. Our customers include category-defining companies like Ramp , Cognition, DoorDash, and Suno. They rely on Modal for instant GPU access, sub-second container starts, and native storage, so it's simple to serve low-latency inference, fine-tune models, and access production-ready sandboxes at scale. We've passed $1B in annualized run rate, up 15x from a year ago. In October 2026 we raised a $750M Series D led by Accel at a $15.75B valuation. Our team includes creators of popular open-source projects (e.g., Seaborn , Luigi ), academic researchers, international olympiad medalists, and experienced engineering and product leaders with decades of experience. The Role: We’re building a platform that covers the whole life of an LLM: training it, deploying it, and observing it in production. We already run multi-node training, elastic inference, sandboxes, and distributed volumes, and we control the infrastructure underneath. We’re looking for research depth in post-training to sit alongside our systems and product work. We are looking for research scientists with a strong track record in reinforcement learning, machine learning, and foundation models, including large language and multimodal models, to join our research team. What You’ll Work On: Improve existing methods and develop new techniques for large-scale model training, optimization, and inference Extend models to long-context and long-horizon tasks Improve inference-time efficiency, reliability, and robustness in high-stakes real-world deployments You May Be a Fit If: You have a PhD in computer science, machine learning, or a related field You have a demonstrated record of research accomplishments in reinforcement learning, machine learning, foundation models, or related fields You have experience with large-scale training and inference infrastructure, including distributed systems and multi-node GPU clusters You’ve developed, trained, optimized, or deployed state-of-the-art large-scale models You have first-author publications at leading venues such as NeurIPS, ICML, ICLR, CoRL, CVPR, UAI, JMLR, or TMLR You have a mission-driven mindset and a strong desire to translate research advances into meaningful product impact You have a collaborative spirit and can work effectively across research and engineering teams Candidates with a master’s degree and significant research or industry experience will also be considered.