Senior Staff Research Scientist

MEET DEEPL DeepL is a global AI product and research company focused on building secure, intelligent solutions to complex business problems. Over 200,000 business customers and millions of individuals across 228 global markets today trust DeepL's Language AI platform for human-like translation, improved writing and real-time voice translation. Founded in 2017 by CEO Jaroslaw “Jarek” Kutylowski, DeepL now has over 1,000 passionate employees and is supported by world-renowned investors including Benchmark, IVP, and Index Ventures. Our goal is to become the global leader in trusted, intelligent AI technology, building products that drive better communication, foster connections, and create a meaningful impact. To achieve this, we need talented people like you to join our journey. If you’re ready to shape the future of AI and grow your career in a fast-moving, purpose-driven environment, DeepL is your next destination. WHAT SETS US APART What sets us apart is our blend of cutting-edge AI technology, meaningful work, and a culture where people truly thrive. We’re a team of innovators, researchers, and creators driven by a shared purpose to unlock human potential by making work simpler, smarter, and more connected. When we share what it’s like to work at DeepL, the reactions are overwhelmingly positive. This might be because of our technology that helps millions of people and businesses communicate and work better every day, or because of the trust, curiosity, and care that shape our culture. What we know for sure is this: being part of DeepL means joining a team dedicated to innovation, growth, and well-being. Discover more about life at DeepL onLinkedIn https://www.linkedin.com/company/deepl/,Instagram https://www.instagram.com/deepl_official/, and our Blog https://www.deepl.com/en/blog. MEET THE TEAM BEHIND THIS JOURNEY: FOUNDATION MODEL TASK ADAPTATION We are the team behind DeepL’s post-training stack for large language models. We focus on developing algorithms and systems that align pre-trained models with tasks and performance goals through techniques like reinforcement learning. As a research-driven team, we stay up to date with current literature to integrate cutting-edge ideas into our core stack. As part of this team, you will shape the future of how our models learn beyond pre-training — enabling new capabilities, better controllability, and safer, more effective user experiences. YOUR RESPONSIBILITIES As a Senior Staff Research Scientist, you’ll lead the design, implementation, and deployment of cutting-edge research in reinforcement learning and post-training at scale. You will define DeepL’s scientific direction in this area, mentor researchers, and drive innovations that make it into production. You will: - Shape scientific strategy and vision for post-training across DeepL, identifying high-leverage directions, setting technical standards and leading research initiatives in a highly dynamic, fast-paced environment - Build and deploy state-of-the-art reinforcement learning pipelines at scale - Post-train large (multi-modal) models to align them with human intent and enable general capabilities such as reasoning, pushing the boundaries of model performance, safety, and efficiency - Drive the entire lifecycle of research and production: from idea conception, theoretical modeling, prototyping, ablation studies, all the way to production deployment - Work closely with cross-functional leadership to shape the technical strategy and priorities of the foundational models research track - Build and foster external collaborations with academic and industrial partners - Set scientific and technical standards for experimentation, reproducibility, and model evaluation - Collaborate deeply with Engineering, ML Platform, and HPC teams to deliver robust and reliable model updates to users - Mentor and guide senior scientists, researchers, and engineers, fostering a culture of excellence, curiosity, and impact QUALITIES WE LOOK FOR We’re looking for a senior-staff-level scientist with a deep technical background, strong leadership skills, and a proven track record of driving research in reinforcement learning or large-scale model alignment to production. - PhD (or equivalent experience) in Computer Science, Machine Learning, Applied Mathematics, Physics or a related field - 5+ years of experience in ML research, including several years leading high-impact projects with responsibilities extending across different teams - Strong expertise in deep reinforcement learning (RLHF/RLAIF/RLVR) - Hands-on experience scaling and deploying LLMs or other foundation models in real-world systems - Strong programming skills and experience working with large compute clusters and ML infrastructure - Excellent communication skills — able to clearly explain complex topics to diverse audiences - Track record of mentoring other scientists and setting techni