Behavioral Science Jobs in Boston, MA (NOW HIRING)

Principal Data Scientist - Quantitative Decision Science & Advanced Analytics
Note: Fidelity will not provide immigration sponsorship for this position.
Are you interested in operating as a senior scientific leader-owning truth, rigor, and decision quality for complex business problems? Fidelity Institutional's AI Center of Excellence (AI CoE) is seeking a Principal Data Scientist to serve as a highly tenured individual contributor and domain authority in data science, quantitative modeling, and advanced analytics.
This role is intentionally Data Science-first, with emphasis on hypothesis-driven analysis, statistical rigor, causal reasoning, and decision science. The Principal Data Scientist is accountable for what the model means, whether it is correct, and whether it should be trusted-not for building or operating production systems.
The Team
The Data Science function within the Fidelity Institutional AI CoE operates as the authority on measurement, experimentation, and quantitative decision-making. The team comprises senior data scientists, statisticians, and quantitative researchers who partner closely with platform, product, BI, and business teams, while maintaining clear ownership of scientific rigor, evaluation frameworks, and analytical truth.
As a Principal Data Scientist, you will operate as a scientific owner and mentor, influencing methodology, standards, and strategic direction across multiple initiatives.
Key Responsibilities
Advanced Data Science & Quantitative Modeling

• Lead hypothesis-driven analyses to answer high-impact strategic and business questions

• Design, develop, and evaluate statistical, econometric, and machine learning models where appropriate

• Ensure models are theoretically sound, empirically validated, interpretable, and fit-for-purpose

• Review and challenge modeling approaches for bias, stability, assumptions, and misuse

Measurement, Evaluation & Decision Science

• Define how success should be measured for complex analytics and AI-enabled initiatives

• Design robust evaluation frameworks including offline validation, back-testing, and live measurement

• Ensure stakeholders can distinguish correlation from causation in analytical results

• Elevate analytics from prediction accuracy to decision quality and business impact

Experimentation & Causal Inference

• Design and review experiments including A/B tests, quasi-experiments, and observational studies

• Apply causal inference techniques (e.g., uplift modeling, DiD, matched controls) to assess incrementality

• Guide best practices for power analysis, inference, and result interpretation

• Serve as a subject-matter expert on "What worked, why, and by how much?"

Advanced Analytics Domains

• Segmentation & Clustering: Design statistically grounded, interpretable segmentations with clear hypotheses and stability checks

• Propensity, Likelihood & Uplift Modeling: Develop probabilistic and causal models to inform prioritization and intervention strategies

• Recommendation & Prioritization Analytics: Guide recommendation logic rooted in statistics, behavioral science, and optimization-not black-box ML

• Behavioral & Journey Analytics: Analyze longitudinal behavior patterns to identify drivers, frictions, and causal levers

• Forecasting & Planning Analytics: Apply time-series and probabilistic forecasting with uncertainty and scenario analysis

• Large Language Models & Generative AI: Design, evaluate, and implement LLM-based solutions - including RAG pipelines, classification, and extraction tasks - with rigorous benchmarking, calibration analysis, hallucination measurement, and bias auditing to ensure outputs are explainable.

Scientific Leadership & Governance (Non-Managerial)

• Act as a senior reviewer and methodological authority across data science initiatives

• Set informal standards for rigor, documentation, and reproducibility

• Mentor senior and mid-level data scientists through technical guidance and peer review

Business Partnership & Influence

• Translate complex quantitative results into clear, decision-oriented narratives for senior stakeholders

• Challenge assumptions and narratives not supported by evidence

• Influence strategy by grounding discussions in data, causality, and expected impact

Expertise and Skills You Bring
Education & Experience

• Master's or PhD in Statistics, Economics, Mathematics, Operations Research, Computer Science, or related quantitative discipline

• 10-14+ years of experience in data science, quantitative research, or advanced analytics

• Proven track record of owning complex analytical problems end-to-end (from question formulation to decision impact)

Core Data Science & Scientific Expertise

• Deep expertise in statistics, probability, and experimental design

• Strong command of causal inference and incrementality measurement

• Solid grounding in forecasting, optimization, and decision science

• Demonstrated ability to assess modeling correctness, assumptions, and limitations

Technical Foundation

• Advanced proficiency in Python for analysis and modeling (NumPy, Pandas, SciPy, Statsmodels, Scikit-learn)

• Strong SQL skills and experience working with large analytical datasets (e.g., Snowflake)

• Hands-on proficiency with large language models and generative AI, including prompt design, retrieval-augmented generation, structured outputs, and agentic workflows, with demonstrated rigor in designing evaluations, defining task-specific metrics, and applying statistical testing to assess reliability, calibration, hallucination risk, and incremental value over non-generative approaches. Equally proficient in hands-on code development as well as the effective use of AI-powered coding assistants, applying both to accelerate analysis while maintaining correctness, reproducibility, and scientific rigor.

Ways of Working

• Thinks like a scientist: hypothesis-first, evidence-driven, and principled

• High bar for rigor, interpretability, and defensibility of results

• Comfortable challenging senior stakeholders using data and logic

• Values clarity, elegance, and correctness over technical novelty

• Operates as a trusted expert rather than a delivery engineer

How This Role Is Distinct

• Senior Individual Contributor: Tenured individual-contributor role with broad organizational influence

• Data Science-First: Focused on analytics, statistics, causality, and decision science

• Strategic Impact: Owns critical analytical questions that shape business decisions and investments

Fidelity's Onsite Working Model
Fidelity is transitioning to a full-time onsite working model through a phased rollout across regions and roles. Currently, some roles and locations require 100% onsite presence, while others require less. Onsite expectations are likely to evolve as the rollout continues. This transition does not apply to fully remote roles.
The base salary range for this position is $126,000-255,000 USD per year.
Placement in the range will vary based on job responsibilities and scope, geographic location, candidate's relevant experience, and other factors.
Base salary is only part of the total compensation package. Depending on the position and eligibility requirements, the offer package may also include bonus or other variable compensation.
We offer a wide range of benefits to meet your evolving needs and help you live your best life at work and at home. These benefits include comprehensive health care coverage and emotional well-being support, market-leading retirement, generous paid time off and parental leave, charitable giving employee match program, and educational assistance including student loan repayment, tuition reimbursement, and learning resources to develop your career. Note, the application window closes when the position is filled or unposted.
Please be advised that Fidelity's business is governed by the provisions of the Securities Exchange Act of 1934, the Investment Advisers Act of 1940, the Investment Company Act of 1940, ERISA, numerous state laws governing securities, investment and retirement-related financial activities and the rules and regulations of numerous self-regulatory organizations, including FINRA, among others. Those laws and regulations may restrict Fidelity from hiring and/or associating with individuals with certain Criminal Histories.
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Data Analytics and Insights