**Company Description** Serasa Experian is the first and largest Datatech in Brazil. A leader in intelligence solutions for risk and opportunity analysis, focusing on credit, authentication, and fraud prevention journeys. With cutting-edge technology, innovation, and top talent, we transform risk uncertainty into optimal decisions, helping individuals achieve their dreams and businesses of all sizes and segments to thrive. We have 22,000 people operating in 32 countries, and every day we invest in new technologies, talented professionals, and innovation to help all our customers maximize every opportunity. Headquartered in Dublin, Ireland, Experian is listed on the London Stock Exchange (EXPN) and is a component of the FTSE 100 index. **Job Description** We are looking for a Data Scientist passionate about Generative AI who combines technical rigor and an experimental mindset to accelerate the next wave of innovation with LLMs. If you enjoy turning models into real-world solutions, precisely measuring impact, and exploring the frontier between science and creativity. **What You'll Do** * Conduct experiments with different LLMs (GPTs, Claude, Gemini, Llama, Deepseek, etc.) applied to business use cases. * Develop evaluation and benchmarking frameworks for GenAI agents (accuracy, relevance, hallucination). * Optimize RAG pipelines by adjusting chunking, embeddings, and retrieval strategies based on real metrics. * Measure agent performance and ROI by creating dashboards and experimentation reports. * Implement A/B tests and comparative analyses of prompts, models, and architectures. * Create domain-specific evaluation datasets and benchmarks. * Support strategic decisions between Fine-Tuning, RAG, or Prompt Engineering. * Document findings and translate results into actionable recommendations for product and technology. **What We’ll Expect From You:** * 5+ years of experience in Data Science/ML, with at least 1 year in GenAI/LLMs. * Proficiency in Python and data science libraries (pandas, scikit-learn, matplotlib). * Experience in NLP, embeddings, and text processing techniques. * Solid knowledge of statistics, experimentation (A/B testing), and data analysis. * Experience evaluating generative models (BLEU, ROUGE, BERTScore, etc.). * Familiarity with LLM and MultiAgent frameworks (OpenAI, LangChain, CrewAI, VannaAI). * Knowledge of SQL and handling large volumes of data. **Nice to Have** * Master's or PhD in quantitative fields (Statistics, Computer Science, Mathematics). * Experience with fine-tuning and transfer learning. * Expertise in ML frameworks (PyTorch, TensorFlow, Hugging Face). * Expertise in automation frameworks and tools (n8n, Flowise, LangFlow). * Experience with prompt optimization (DSPy, Automatic Prompt Engineering). * Knowledge of model interpretability and explainability. * Familiarity with visualization tools (Plotly, Streamlit, Tableau). **Qualifications** * LLM * GenAI * DataScience * Multi Agents * Prompt * BigData **Additional Information** At Serasa Experian, we believe diversity is essential for a healthier and more innovative workplace where everyone can share experiences and express their ideas. Therefore, we implement various initiatives to promote inclusive hiring and support professional development. Additionally, we have affinity groups created to empower and support underrepresented groups: ExperianPride (LGBTQIAPN+ community), Ubuntu (racial equity), Women in Experian (gender equity), Aspire (people with disabilities), and Connecting Generations (generations). Join us in this transformation! **#LI-HYBRID** Experian Careers - Creating a better tomorrow together Find out what its like to work for Experian by clicking here