Senior Data Scientist, Growth (f/m/x)

HelloFresh
Berlin, Germany
On-site

Who this role is best for

A natural match if you have experience in marketing analytics and machine learning model deployment.

Best fit for

  • Candidates with 3+ years in marketing or e-commerce data science roles
    — “3+ years of professional experience as a (senior) data scientist or in a related quantitative role, ideally in e-commerce, marketing, or a comparably high-traffic, consumer-facing environment.”
  • Individuals who have shipped models in production and optimized conversion funnels
    — “rigorous modeling, close collaboration with engineering and marketing stakeholders, and a bias toward shipping models that work in production, not just in a notebook.”
  • Candidates with strong statistical modeling and experimentation experience
    — “Experimentation: design tests, define success metrics and guardrails, and interpret results while accounting for statistical uncertainty, noise, and bias.”
  • Candidates who can build and manage data pipelines and analyze heterogeneous datasets
    — “Retrieve, manipulate, and analyze large, heterogeneous datasets, and build the data pipelines your models depend on.”
  • Candidates with experience in customer segmentation and behavioral data analysis
    — “Conversion & personalization: experience building decisioning or recommendation models that run in production behind high-traffic conversion funnels; customer segmentation and behavioral data.”

Things to consider

  • The role demands a strong ability to interpret results under real-world uncertainty
    — “comfortable with statistical uncertainty, and can translate a fuzzy business question into a concrete, testable model.”
  • Candidates must be able to work in an international environment with diverse stakeholders
    — “collaborative team player with exceptional communication skills, able to work with stakeholders from different backgrounds in an international environment.”

How to stand out

  • Highlight experience with media mix models or incrementality measurement in your resume
    — “experience with media mix models, attribution modeling, or incrementality measurement”
  • Emphasize your ability to design and interpret experiments with guardrails
    — “define success metrics and guardrails, and interpret results while accounting for statistical uncertainty, noise, and bias.”
  • Showcase your ability to build end-to-end data pipelines and models
    — “build the data pipelines your models depend on.”
  • Demonstrate your experience with reinforcement learning or contextual bandits
    — “direct experience with reinforcement learning or contextual bandits (e.g. Thompson Sampling, epsilon-greedy)”
  • Include examples of how you have influenced architecture or design decisions
    — “Technical/Product/Design leadership: Drive best practices and influence architecture/design, quality, and ways of working in an autonomous, product-led setup.”
Pace · SteadyCollaboration · HighAutonomy · MediumDecision Impact · Team

Derived from job-description analysis by Serendipath's career intelligence engine.

What success looks like

  • designing and shipping statistical and machine learning models
  • translating business objectives into data-driven strategies
Typical background
data sciencemarketing analytics

Skills & requirements

Required

Statistical ModelingMachine LearningData AnalysisExperimentationCross-functional Collaboration

Preferred

Marketing TechnologyGrowth Optimization

Stack & domain

Statistical And Machine Learning ModelsMarketing BudgetConversion FunnelPersonalizationMarketing MeasurementChannel OptimizationFunnel OptimizationCustomer CommunicationsExperimentationData AnalysisData PipelinesPythonNumPyPandasscikit-learnMatplotlibSQLDatabricks/sparkSoftware Engineering PracticesGitDockerAWSGen AI ToolsProblem SolvingPrioritizationStatistical UncertaintyCommunicationCollaborationCoachingMarketingGrowthE-commerceConsumer-facing Environment

About the role

Original posting from HelloFresh

About the role: What's in the Box

The Growth Alliance powers HelloFresh’s marketing engine, from media investment and in-channel optimization, to the conversion funnel, to how and when we communicate with customers. As a Senior Data Scientist, you will design and ship statistical and machine learning models that turn data from experiments, campaigns, and customer behavior into decisions that directly move the business: how we spend our marketing budget, how we convert visitors into customers, and how we personalize every touchpoint along the way.

You’ll join one of several teams within the alliance, spanning marketing measurement and attribution, channel optimisation, funnel optimisation and decisioning on customer communications and messaging. Across all of these topics, the through line is the same: rigorous modeling, close collaboration with engineering and marketing stakeholders, and a bias toward shipping models that work in production, not just in a notebook.

To succeed in this role, you should be a curious, pragmatic problem solver who relentlessly prioritizes based on impact, is comfortable with statistical uncertainty, and can translate a fuzzy business question into a concrete, testable model.

At HelloTech, flexibility and cross-functional collaboration are core to how we work. While this role is aligned to a specific Alliance, strong candidates may also be considered for opportunities across different teams or projects.

What you’ll do: The Recipe

Design, build, and take ownership of statistical and machine learning models, from data collection through to production, closely aligning the approach with non-technical stakeholders.

Collaborate within cross-functional teams (engineering, product, marketing) to translate business objectives into concrete, data-driven strategies.

Experimentation: design tests, define success metrics and guardrails, and interpret results while accounting for statistical uncertainty, noise, and bias.

Continuously iterate and refine your technical approach, monitor model performance, data reliability, and drift once in production.

Retrieve, manipulate, and analyze large, heterogeneous datasets, and build the data pipelines your models depend on.

Think beyond the immediate ask to find new ways to improve the data products delivered to stakeholders.

As a senior member of the team, jump in to help solve problems as they arise, and support and coach more junior data scientists.

What you’ll bring: The Ingredients 

Proven track record of scientific work through a Bachelor’s, Master’s, or PhD in statistics, physics, economics, mathematics, data science, or a related quantitative field.

3+ years of professional experience as a (senior) data scientist or in a related quantitative role, ideally in e-commerce, marketing, or a comparably high-traffic, consumer-facing environment.

Strong marketing and/or growth domain knowledge, with experience applying statistical models such as regressors and classifiers, and interpreting experiment results under real-world uncertainty.

Fluency in Python and its scientific stack (NumPy, Pandas, Scikit-learn, Matplotlib); comfortable retrieving and analyzing data with SQL. Experience with Databricks/Spark is a plus.

Familiarity with software engineering practices and tools (Git, Docker, AWS or similar cloud environments).

Comfortable using recent Gen AI tools (e.g. Claude Code) to design and build solutions in a structured and pragmatic manner.

A critical thinker and creative problem solver who is comfortable proposing and prioritizing multiple solutions based on effort and likely impact.

A collaborative team player with exceptional communication skills, able to work with stakeholders from different backgrounds in an international environment.

Nice to have (domain specific), if you find yourself in one of the below, it’s a huge plus!

Measurement & attribution: experience with media mix models, attribution modeling, or incrementality measurement; Bayesian forecasting and estimating model uncertainty.

Search or Social channel optimization: experience with the Google/Meta ecosystem or other paid channels, forecasting algorithms, portfolio optimization, or Vector Autoregression.

Conversion & personalization: experience building decisioning or recommendation models that run in production behind high-traffic conversion funnels; customer segmentation and behavioral data.

Messaging & send decisioning: direct experience with reinforcement learning or contextual bandits (e.g. Thompson Sampling, epsilon-greedy), off-policy/counterfactual evaluation, or CRM and marketing decisioning use cases.

What we offer: The Toppings

Global collaboration at scale: Collaborate with experienced engineers and product partners across HelloTech’s international teams, in a culture of active knowledge sharing.

Technology with real-world impact: Build and operate modern systems at global scale, supporting 6+ millions of customers and complex supply chain operations.

Technical/Product/Design leadership: Drive best practices and influence architecture/design, quality, and ways of working in an autonomous, product-led setup.

End-to-end development/delivery: Drive decisions from problem definition to production, improving systems and enabling long-term scalability.

Are you the missing ingredient? If this sounds like a tasty opportunity, we’d be excited to hear from you. We aim to review your profile and respond within 5 business days.

#DATA

Source: HelloFresh careers

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