Role overview:

We are seeking an exceptional Data Scientist with deep expertise in advanced AI systems, particularly in the design, deployment, and optimisation of Large Language Models (LLMs) beyond standard usage patterns. Descartes & Mauss is the first AI Powered Growth Strategy Platform. Our platform helps companies take better decisions, faster. In 2024, we have successfully raised €5.5 million in funding from Elaia and Polytechnique Ventures.

As a Senior Data Scientist at D&M, you will:

• Advance LLMs: Develop, fine-tune, and optimise large language models for specialised tasks, integrating structured and unstructured data sources.

• Build Agentic AI: Design multi-agent systems and autonomous tool-using agents capable of reasoning, planning, and orchestration across APIs, databases, and knowledge graphs.

• Contribute to AGI research: Prototype novel cognitive architectures, explore reinforcement learning and emergent behaviours, and push the boundaries of adaptability and reasoning.

• Apply advanced mathematics: Use optimisation, probability, statistics, and graph theory to design robust models, evaluation metrics, and simulations.

• Identify growth opportunities: Apply AI-driven analytics to map emerging domains and support strategy teams with predictive insights

• AI/ML Foundations: 5+ years in Data Science, Machine Learning, or Applied AI with strong expertise in NLP, deep learning (Transformers, RNNs, etc.), and generative AI. Proficiency in Python and major ML frameworks (PyTorch, TensorFlow, JAX).

• LLMs & Agentic AI: Hands-on experience with open-source and proprietary LLMs (e.g., LLaMA, GPT, Claude, Mistral, Gemini). Practical work with agentic AI frameworks (LangChain, CrewAI, AutoGPT, or custom architectures).

• Data Infrastructure: Strong SQL/NoSQL skills, data pipeline design, and familiarity with vector databases (Pinecone, Weaviate, FAISS) and graph databases (Neo4j, AWS Neptune). Experience with cloud platforms (AWS preferred).

• Mathematics & Modelling: Solid background in applied mathematics, probability, statistics, optimisation, and graph theory. Skilled in building explainable, validated models and time-series forecasting.

• Strategic Insight: Ability to translate technical findings into business opportunities, identify market trends, and support innovation roadmaps.

• Nice-to-have: Published research, open-source contributions, multi-modal AI experience, reinforcement learning expertise, and comfort in fast-paced, experimental environments.

What you’ll love about working at Descartes & Mauss

• Work from home (or wherever you perform best) up to 3 days per week
  -> every Wednesdays & Thursdays we meet at our WeWork space in Paris 9ème. Our coworking space accepts dogs, so your furry friend can come along 🐶
  -> you’ll have a WeWork card to use their offices worldwide

• Extended full remote periods during summer and the end of the year, allowing you to spend more time with loved ones

• 18+ nationalities represented (and growing!) and 50-50 gender balance, ensuring equal opportunities for all

• 3 company-wide workshops per year, some featuring expert speakers! And an international company offsite every year - our last one was in Tuscany in 2024!

• 50% of Navigo transportation costs reimbursed

• Swile card for meals, with a daily allowance of €16, 55% covered by us

• An extra day off on your birthday apart from 25 days off + RTTs  🎊

• Buddy program for all newcomers, ensuring a smooth integration with guidance from experienced team members

• Access to training resources and mentorship from experienced peers and managers

• 30 mins chat with HR team

• 30 mins chat with the hiring manager

• A Case Study

• Office tour & meet the team (if you’re Paris based) - if your team is based in Paris, we’d love to invite you to our office for a quick tour and to meet them in person!

D&M celebrates diversity and is committed to creating an inclusive environment for all employees. Studies show that women and people from underrepresented groups often hesitate to apply unless they meet all the criteria. If you’re excited about this role but don’t meet every single requirement, we encourage you to apply anyway. You might be just the person we need!