Senior Data Scientist, Experimentation (Marketing)

Fractal; San Francisco (CA); On-site; USD 120,000 - 175,000; Full time

Benefits offered by this job

Health, dental, and vision insurance

Discretionary bonus

401(k) plan with company match

Paid holidays and parental leave

Flexible PTO policy

Job summary

A leading data science firm in San Francisco seeks a Senior Data Scientist to spearhead experimentation methodologies. This role involves designing A/B tests, enhancing a proprietary experimentation platform, and collaborating with cross-functional teams to optimize marketing performance. Candidates should carry 7-10 years of experience in data science, ideally within a marketing context, along with a strong command of statistical techniques and project management skills. A competitive salary ranging from $120,000 to $175,000 is offered, along with robust benefits.

Qualifications

• Deep expertise in statistical methods and hypothesis testing.
• Experience in causal inference for always-on marketing contexts.
• Minimum 7-10 years of experience in data science or quantitative analytics.

Responsibilities

• Own statistical design and analysis of A/B tests.
• Define statistical methods for proprietary experimentation platform.
• Collaborate with teams to improve the experimentation program.

Skills

Experimentation design

Statistical hypothesis testing

Causal inference methods

Data querying (SQL)

Scripting (Python or R)

Excellent communication skills

Project management

Education

Bachelor's degree in Statistics, Data Science, or related fields

Master's or PhD in a quantitative discipline

Tools

Adobe Target

Optimizely

Job description

Note: This position is not eligible for Immigration Sponsorship at this time.

Fractal is a strategic AI partner to Fortune 500 companies with a vision to power every human decision in the enterprise. Fractal is building a world where individual choices, freedom, and diversity are the greatest assets. An ecosystem where human imagination is at the heart of every decision. Where no possibility is written off, only challenged to get better. We believe that a true Fractalite is the one who empowers imagination with intelligence. Fractal has been featured as a Great Place to Work by The Economic Times in partnership with the Great Place to Work® Institute and recognized as a ‘Cool Vendor’ and a ‘Vendor to Watch’ by Gartner.

Please visit Fractal | Intelligence for Imagination for more information about Fractal.

Summary:

We're looking for a top-notch Senior Data Scientist to lead the design, execution, and statistical methodology of our experimentation program. You will join our cross-functional Optimization team comprised of Data Scientists, Creatives, Developers, and Producers. You will own end-to-end test analysis, drive the statistical methodology underpinning Stats Engine, and serve as the technical authority on experimentation best practices across the client’s marketing organization which includes Channel Digital, email marketing, social media, and paid media.

If you're passionate about the intersection of marketing, data science, and experimentation — and are energized by the opportunity to shape how a world-class brand makes data-driven decisions at scale — we encourage you to apply.

KEY QUALIFICATIONS

• Deep expertise in experimentation design and statistical hypothesis testing — including sample size determination, power analysis, confidence intervals, p-values, and multiple testing corrections.
• Strong command of advanced statistical methods including sequential testing (SPRT, alpha-spending functions), variance reduction techniques (CUPED), and Bayesian inference.
• Experience with dynamic optimization methods such as Multi-Armed Bandits (Thompson Sampling, Upper Confidence Bound) and their application in marketing or digital product contexts.
• Proficiency in causal inference methods including synthetic control, Difference-in-Differences, and quasi-experimental design — particularly for geo-targeted or always-on marketing contexts where traditional A/B testing is not feasible.
• Strong data querying skills (SQL) and fluency in a scripting language (Python or R) for statistical analysis, data wrangling, and results automation.
• Excellent communication and presentation skills with the ability to translate complex statistical findings into clear, actionable insights for diverse audiences including creatives, producers, and marketing leaders.
• Proven ability to manage multiple experimentation projects across different stages of development simultaneously, with strong attention to detail and quality standards.
• Team player who thrives in a cross-functional environment and takes pride in elevating the statistical rigor of the teams around them.

Highly beneficial (but not required)

• Experience with multi-geo test execution and localization considerations across global markets.
• Familiarity with experimentation platforms such as Adobe Target or Optimizely, and experience partnering with platform engineering teams on analytics implementation.
• Experience applying ML algorithms — regression, decision trees, clustering — to marketing measurement or audience segmentation problems.
• Background in marketing analytics, digital attribution, or media measurement.

DESCRIPTION

Core responsibilities cover three pillars:

EXPERIMENT DESIGN & ANALYSIS:

Own the end-to-end statistical design and analysis of A/B tests across, email (DM), and Channel Digital platforms. Develop test proposals that define populations, KPIs, runtime requirements, and minimum detectable effects. Analyze results with rigor, develop clear insights, and deliver recommendations that drive confident decision-making.

Apply advanced statistical methods — including sequential testing, CUPED variance reduction, and Bayesian approaches — to increase the speed and sensitivity of the experimentation program. Apply causal inference methods for always-on optimization scenarios and geo-targeted campaigns where traditional A/B testing is not feasible.

STATS ENGINE METHODOLOGY & PLATFORM:

Serve as the statistical methodology owner for Stats Engine — Client's proprietary experimentation platform. Define, validate, and document the statistical methods embedded in the platform, ensuring all automated calculations meet the highest standards of accuracy and rigor.

Partner with the Product Manager and Client's AiDP engineering team to translate methodological requirements into platform specifications. Contribute to the evolution of Stats Engine through Phases 2–4, including sequential testing support, automated result analysis, and AI-powered experimentation features.

RESEARCH & DEVELOPMENT:

Partner with Data Scientists across Marketing, Retail, and Operations on projects to increase the sophistication of the experimentation program and deliver deeper insights about marketing performance. Identify opportunities to introduce new statistical techniques — such as Multi-Armed Bandits, synthetic control, and opportunity sizing models — that expand the program's analytical capabilities.

Contribute to the development of scalable, reusable analytical frameworks and documentation that codify best practices and reduce the per-test analytical burden over time, supporting the program's goal of scaling to 150+ tests annually.

EDUCATION & EXPERIENCE:

• Bachelor's degree with quantitative emphasis. Statistics, Data Science, Mathematics, Operations Research, Computer Science, or related field.
• Master's or PhD in a quantitative discipline strongly preferred.
• Minimum 7–10 years of relevant industry experience in experimentation, data science, or quantitative analytics, with at least 3 years in a marketing or digital analytics context.

Pay:

The wage range for this role takes into account the wide range of factors that are considered in making compensation decisions, including but not limited to skill sets; experience and training; licensure and certifications; and other business and organizational needs. The disclosed range estimate has not been adjusted for the applicable geographic differential associated with the location at which the position may be filled. At Fractal, it is not typical for an individual to be hired at or near the top of the range for their role and compensation decisions are dependent on the facts and circumstances of each case. A reasonable estimate of the current range is: $120,000 - $175,000. In addition, you may be eligible for a discretionary bonus for the current performance period.

As a full-time employee of the company or as an hourly employee working more than 30 hours per week, you will be eligible to participate in the health, dental, vision, life insurance, and disability plans in accordance with the plan documents, which may be amended from time to time. You will be eligible for benefits on the first day of employment with the Company. In addition, you are eligible to participate in the Company 401(k) Plan after 30 days of employment, in accordance with the applicable plan terms. The Company provides for 11 paid holidays and 12 weeks of Parental Leave. We also follow a “free time” PTO policy, allowing you the flexibility to take the time needed for either sick time or vacation.

Fractal provides equal employment opportunities to all employees and applicants for employment and prohibits discrimination and harassment of any type without regard to race, color, religion, age, sex, national origin, disability status, genetics, protected veteran status, sexual orientation, gender identity or expression, or any other characteristic protected by federal, state or local laws.