Senior Data Scientist

What Expel Can Do For You

• Provide opportunities where your decisions have a direct impact on our company and our customers
• Give you real, hard problems at the frontier of both GenAI and traditional ML in a security context
• Empower you to scale yourself by teaching others what responsible, non-hyped AI looks like in practice
• Challenge you to push the boundaries of our data science, security, and technology vision
• Offer an entertaining, small, and highly transparent environment where your voice matters

What You Can Do For Expel

• Build and ship ML and GenAI systems — from anomaly detection models to LLM-powered analyst tools and agentic workflows — across the full lifecycle from research to production
• Bring stakeholders along by clearly communicating the what, why, and how of your work, including successes and failures
• Work across operations, engineering, and service delivery to ensure our AI and ML capabilities are easy to deploy, monitor, and maintain
• Partner with subject matter experts to explore where prompt engineering, knowledge retrieval, and agentic AI can deliver real value alongside classical approaches
• Foster an atmosphere of experimentation, continuous learning, and improvement
• Stay current on emerging techniques, papers, and tools — and bring relevant ideas back to the team
• Mentor and coach other data scientists and curious non-DS colleagues

What You Should Bring With You

• 4+ years of professional data science experience building and shipping models in production
• Solid grounding in traditional ML: classification, regression, anomaly detection, clustering, time series — using frameworks like scikit-learn or statsmodels
• Hands-on experience with large language models, prompt engineering, and LLM application architectures including knowledge retrieval and grounding (e.g., embeddings-based search, vector stores)
• Experience building or contributing to LLM-powered agentic systems, including tool use and orchestration with frameworks like LangChain, LlamaIndex, or similar
• Strong Python and SQL skills, utilizing core data libraries (pandas/numpy) and visual toolkits (plotly/seaborn/matplotlib) to transform complex analysis into clear, actionable insights for stakeholders and cross-functional peers
• Solid statistical foundations: distributions, hypothesis testing, probability, and the wisdom to know when a simpler model is the right one
• Exemplary collaboration skills that result in higher levels of team confidence and morale, streamlining requirements gathering