Data Scientist

Arena

Data Scientist analyzing complex datasets to derive insights for AI evaluations. Collaborating with ML researchers to enhance reliability of AI systems in a hybrid work environment.

Posted 4/12/2026full-timeBay Area • California • 🇺🇸 United StatesMid-LevelSeniorWebsite

Tech Stack

Tools & technologies

NumpyPandasPythonSpark

About the role

Key responsibilities & impact

Explore and analyze large, complex datasets to uncover patterns, biases, and causal relationships in model behavior and system performance.
Formulate hypotheses about data quality, evaluation outcomes, and model performance — then design experiments to validate or refute them.
Build reproducible analysis pipelines using Python, Pandas, NumPy, and Spark to process and interrogate large-scale data.
Partner with ML researchers and engineers to design metrics and analyses that evaluate how models perform across domains, prompts, and tasks.
Develop causal reasoning frameworks and statistical methods that help explain why models behave as they do — not just how well they perform.
Communicate insights (for example, via blog posts) clearly to technical and non-technical partners, informing both research direction and infrastructure improvements.

Requirements

What you’ll need

6+ years of experience in data science, ML analytics, or applied research, preferably in AI, ML, or large-scale data environments.
Strong proficiency in Python, with deep experience in Pandas, NumPy, and distributed frameworks like Spark.
Expertise in statistical modeling, causal inference, and experimental design.
Experience reasoning about data distributions, sample quality, and the effects of data distribution shifts.
Strong communication skills and the ability to collaborate closely with ML researchers and engineers.
(Bonus) Background in AI model evaluation.
(Bonus) Experience working with LLM outputs (for example, LLM-as-a-judge), embeddings, or other large-scale model artifacts.
(Bonus) Experience with A/B testing.

Benefits

Comp & perks

Comprehensive health and wellness benefits, including medical, dental, vision, and additional support programs.
The opportunity to work on cutting-edge AI with a small, mission-driven team
A culture that values transparency, trust, and community impact

ATS Keywords

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Applicant Tracking System Keywords

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Hard Skills & Tools

data sciencemachine learning analyticsapplied researchstatistical modelingcausal inferenceexperimental designdata distributionsdata qualityA/B testinglarge-scale data processing

Soft Skills

strong communication skillscollaborationinsight communication