Note: The job is a remote job and is open to candidates in USA. Expel is seeking a Senior Data Scientist to solve meaningful security and operational problems using traditional machine learning and generative AI. The role involves building production ML and GenAI systems, developing metrics and threat detection models, designing AI-powered analyst tools, collaborating with cross-functional teams, and mentoring others.
Responsibilities
- 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
Skills
- 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 to drive superior output
- Ability to communicate technical concepts clearly to non-technical audiences
- Passion for finding order and meaning in large, chaotic data sets
- We're only hiring those authorized to work in the United States
- Domain experience in cybersecurity (anomaly detection, threat hunting, risk scoring) is a strong plus
Benefits
- Bonus eligibility
- Equity
- Unlimited PTO (which we model and encourage)
- Work location flexibility
- Up to 24 weeks of parental leave
- Really excellent health benefits
Company Overview