Data Scientist II

Must have Ad Tech / MarTech industry experience, specifically in e-commerce, travel, and finance.

In this client-facing Data Scientist role at CJ, you will serve as a dedicated analytics partner to a large enterprise client, delivering data-driven insights and advanced analytical solutions in a digital advertising environment. You will own end-to-end projects that support campaign performance, measurement, and optimization, helping drive growth through high-quality data, clear reporting, and actionable recommendations.

You will work closely with client stakeholders, account teams, and cross-functional partners to translate business needs into scalable data solutions. This role is ideal for someone who thrives in a fast-paced, client-facing environment and enjoys combining technical expertise with strategic problem-solving to influence marketing outcomes.

What you will do:

• Lead and support advanced client-facing data science and analytics projects, including forecasting, incrementality measurement, and program optimization.
• Act as a strategic partner to account teams, proactively identifying opportunities, shaping measurement strategies, and influencing decision-making.
• Apply hypothesis-driven analysis to diagnose performance and quantify impact.
• Take ownership of project scoping, data querying and modeling, quality checks, and delivery of actionable insights.
• Analyze large-scale e-commerce and advertising datasets, leveraging statistical and ML methods to uncover opportunities and support growth strategies.
• Design and interpret incrementality tests, marketing mix models (MMM), and lift tests to assess causal impact and optimize marketing spend.
• Develop machine learning models, including forecasting and inferential analysis, and implement LLM-driven solutions where applicable.
• Create and deliver Tableau dashboards and reporting that distill complex analysis into clear, actionable insights for both internal and external stakeholders.
• Collaborate with account teams, engineers, and other data scientists to design and implement scalable data solutions.
• Present technical findings and recommendations to non-technical audiences, demonstrating strong client-facing and communication skills.
• Present complex analytical concepts in intuitive ways tailored to varying levels of stakeholder sophistication.

• 3-5 years of professional experience in Data Science and Analytics.
• 2+ years of hands-on experience with PySpark, Scala, and Tableau.
• Must have Ad Tech / MarTech industry experience, specifically in e-commerce, travel, and finance.
• Strong client-facing experience, including presentations and solution delivery.
• Proven ability to deliver scalable data solutions and actionable insights in digital advertising or affiliate marketing.
• Proficiency with GitLab or GitHub for version control and collaborative development.
• Experience developing alongside LLM code assistants (e.g., Copilot, Claude, Codex).
• Preferred: Experience implementing LLMs into business workflows, including training, fine-tuning, and manipulation for applied use cases.
• Experience with incrementality testing, MMM, and lift test design and analysis.
• Strong communication skills with the ability to simplify and explain complex technical results to non-technical stakeholders.

35 West Wacker Drive, Chicago, IL 60601 Hybrid work $120,064 - $135,632 a year