Senior Research Scientist

Meet DeepL

DeepL is a global communications platform powered by Language AI. Since 2017, we've been on a mission to break down language barriers. Our human‑sounding translations and intelligent writing suggestions are designed with enterprise security in mind. Today, they enable over 100,000 businesses to transform communications, reach new markets, and improve productivity. And, empower millions of individuals worldwide to make sense of the world and express their ideas.

Our goal is to become the global leader in Language AI, building products that drive better communication, foster connections, and make a real‑life impact. To achieve this, we need talented individuals like you to join our exciting journey. If you're ready to work with a dynamic team and build your career in the fast‑moving AI space, DeepL is your next destination.

What sets us apart is our blend of modern technology, competitive benefits, and an open, welcoming work culture that enables our people to thrive. When we share what it's like to work at DeepL, the reactions are overwhelmingly positive. This may be because of our products that have helped countless people worldwide or our shared mission to improve communication for individuals and businesses, bringing cultures closer together.

What we know for sure is this: being part of DeepL means joining a team dedicated to innovation and employee well‑being. Discover what our teams have to say about life at DeepL on Linked In, Instagram and our Blog.

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 cont rollability, and safer, more effective user experiences.

As a Senior Staff Research Scientist, you'll lead the design, implementation, and deployment of cutting‑edge research in reinforcement learning and post‑training  will define DeepL's scientific direction in this area, mentor researchers, and drive innovations that make it into production.

• 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

• 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 technical long‑term vision

You are welcome at DeepL for who you arewe appreciate authenticity here. Our product is for everyone, and so is our workplace. The more voices we have represented and amplified in our business, the more we will all succeed, contribute, and think forward! So bring us your personal experience, your perspectives, and your background. Its in our diversity that we will find the power to break down language barriers in the world.