Senior Data Scientist

At Humara we're developing the next generation of virtual sales assistants. With genAI at our core, we help users discover products that truly fit their needs, provide Product Experts to answer their questions 24/7, and guide them through complex sales processes in any channel they choose. We're looking for a Senior Data Scientist to join our established team and be a hands-on contributor to new and existing features of our multi-agent conversational sales product, with a focus on agentic and LLM-driven systems that perform reliably in production and drive conversion. You'll work alongside a multi-skilled group of data scientists, AI engineers and MLOps specialists in cross-functional teams. We deliver against quarterly OKRs, own our work end to end, and put collaboration at the heart of how we operate. Requirements Strong ML experience, hands-on NLP and production experience with agentic AI are essential. Our stack includes AWS, Python, PyTorch, Docker, LangChain/LangGraph and Langfuse. Experience with reinforcement learning or an understanding of sales psychology would be desirable plus there's plenty of ambitious work now and upcoming. The person we're looking for Enjoys tackling hard, open-ended problems and seeing the solution through to real users Has a get-things-done mindset and takes work from idea to delivery Keeps learning and stays current in a fast-moving field Practical and collaborative: argues a position with conviction, and changes it when the evidence says so Explains technical ideas clearly to engineers and commercial teams alike Works independently and manages their own time and priorities well You'll be responsible for Designing, building and shipping LLM and agent-based systems, from first prototype to live product Building retrieval pipelines (RAG, ranking, recommendation, summarisation, grounded Q&A) Training, fine-tuning and optimising models, mainly for language tasks Defining how we measure success, through offline evals, experiments and production monitoring tied to user and commercial outcomes Keeping systems dependable, with automated testing, observability, troubleshooting and incident response Setting the bar for code quality, security, data governance and documentation Working closely with engineering, data and product teams, and mentoring others Skills and experience Extensive experience in data science and ML, including hands-on delivery of LLM-powered and agentic systems running in production at scale Works AI-natively day to day, using AI tools and agents as a core part of how they build, test and ship Strong Python, plus PyTorch, scikit-learn or similar frameworks Hands-on LLM work: prompting, fine-tuning, grounding and guardrails Agentic systems at scale, including orchestration (LangChain/LangGraph), tracing and evals (Langfuse), memory design, and latency and cost trade-offs Embeddings, vector search and hybrid search Solid grounding in statistics and ML theory across…