Senior Research Scientist FMTA

Your responsibilities

As a Senior Research Scientist, you’ll design, implement, and deploy cutting-edge research in reinforcement learning and post-training at scale, driving innovations that make it into production.

You will:

• 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.
• Always keep the entire lifecycle of research and production in mind: from idea conception, theoretical modeling, prototyping, ablation studies, all the way to production deployment.
• Build and foster external collaborations with academic and industrial partners.
• Follow 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.

Qualities we look for

We’re looking for a 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.

We are seeking researchers with a strong practical background, a creative mindset, and a passion for solving hard problems with real-world impact.

You have a solid mathematical background and enjoy solving challenging problems, evidenced by a masters degree, diploma, PhD, or equivalent industry experience in mathematics, physics, computer science, or a related field.

Deep practical experience in Python and at least one modern machine learning framework such as PyTorch, TensorFlow, or JAX, experience working with large compute clusters and ML infrastructure is a plus.

A track record of leading self-directed research projects that go well beyond academic exercises and deliver tangible results.

Expertise in deep reinforcement learning (RLHF/RLAIF/RLVR) is a plus.

Hands-on experience scaling and deploying LLMs or other foundation models in real-world systems is a plus.

What we offer

• Diverse and internationally distributed team: joining our team means becoming part of a large, global community with people of more than 90 nationalities. We're more than just colleagues; we're a group of professionals with a shared mission to connect diverse cultures. Our global presence is growing–we've doubled in size nearly every year, with our employees based in the UK, Germany, the Netherlands, Poland, the US, and Japan, and we continue to expand our network.
• Open communication, regular feedback: as a language-focused company, we value the importance of clear, honest communication. We value smooth collaboration, direct and actionable feedback, and believe that leading with empathy and growth mindset makes us better together.
• Hybrid work, flexible hours: we offer a hybrid work schedule, with team members coming into the office three times a week. This allows you to engage directly with your team and experience the unique energy of our workspace, while still enjoying the flexibility and comfort of working from home. With flexible working hours and trust in your productivity, we are in sync with your team’s general locations and time zones to foster effective and seamless collaboration.
• Monthly full-day hacking sessions: every month, we have Hack Fridays, where you can spend your time diving into a project you're passionate about and get the opportunity to work with other teams–we value your initiatives, impact, and creativity.
• 30 days of annual leave: we value your peace of mind. With 30 days off (excluding public holidays) and access to mental health resources, we make sure you're as strong mentally as you are professionally.
• Competitive benefits: just as our team spans the globe, so does our benefits package. We've crafted it to reflect the diversity of our team and tailored it to align with your unique location, to ensure you feel supported every step of the way.

If this role and our mission resonate with you, but you're hesitant because you don't check all the boxes, don't let that hold you back. At DeepL, it's all about the value you bring and the growth we can foster together. Go ahead, apply—let's discover your potential together. We can't wait to meet you!

We are an equal opportunity employer

You are welcome at DeepL for who you are - we 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. It’s in our diversity that we will find the power to break down language barriers in the world.