Senior AI Research Scientist – NLP, IR & LLMs (Remote Spain)

About the role

NielsenIQ, a consumer intelligence company, is hiring a Senior AI Research Scientist to work remotely from Spain. The role focuses on assessing and adapting state-of-the-art techniques in recommender systems, NLP and information retrieval, and applying them to large-scale business problems. It suits someone with a deep understanding of machine learning who can present clearly to non-technical audiences.

Key responsibilities

• Research, evaluate and adapt state-of-the-art techniques to solve large-scale AI problems, with minimal supervision.
• Drive innovation in information retrieval, product matching, recommendation systems, NLP and generative AI.
• Assess emerging research and identify adoption opportunities across business initiatives.
• Design and run advanced experiments and feasibility studies to guide technical strategy.
• Develop scalable, reproducible and maintainable ML solutions and research frameworks.
• Collaborate with Applied AI and Engineering teams, mentor other scientists and lead or contribute to publications, patents and conference submissions.
• Communicate research findings and strategic recommendations to stakeholders and promote scientific rigor.

Required profile

• Master's or PhD in Computer Science, AI, Machine Learning, Mathematics, Physics or a related quantitative discipline.
• 7+ years of experience in machine learning, deep learning or AI research.
• Expertise in training transformer-based models for information retrieval, recommendation systems, product matching or NLP.
• Experience training custom small language models and/or small reasoning models.
• Ability to understand, evaluate and extend ideas from scientific literature, and to drive research initiatives independently.

Required skills

• Advanced Python, PyTorch, Hugging Face, Pandas, Scikit-learn and Git.
• Transformer architectures, embeddings and representation learning.
• Vector databases such as FAISS, ChromaDB and Pinecone, and retrieval-based systems.
• Good to have: RAG, LLMs, agent-based frameworks, knowledge graphs, Databricks, SQL, Elasticsearch, and retail/consumer intelligence experience.

What we offer

• Salary of 55,300 to 70,000 EUR gross per year, possibly with a performance-based bonus.
• Home office model with occasional team meetings at the Madrid office.
• Flexible working environment, volunteer time off, LinkedIn Learning and an employee assistance program.