Senior Data Scientist, Growth Alliance (m/f/d)

HelloFresh; Warszawa; On-site; PLN 240,000 - 360,000; Full time

Benefits offered by this job

Global collaboration

Access to modern workspace

End-to-end development opportunities

Job summary

A leading meal kit company in Warsaw is seeking a Senior Data Scientist to contribute to personalized user journeys. This role involves building machine learning models and optimizing conversion funnels in collaboration with Product and Engineering teams. Candidates should have over 5 years in data science, strong machine learning foundations, and effective communication skills. The position offers opportunities for global collaboration and access to modern office facilities.

Qualifications

• 5+ years of professional experience in data science or a related quantitative field.
• Hands-on experience with machine learning techniques.
• Practical experience designing and analyzing A/B tests.
• Experience designing and analyzing A/B tests.
• Experience with customer behavior data and segmentation.
• Production experience collaborating with engineers.
• Clear, structured communication and collaboration.

Responsibilities

• Build and iterate on machine learning models for personalization.
• Execute decisioning models in the conversion funnel.
• Coordinate with Engineering for integrating data science solutions.
• Collaborate with Product and Engineering to embed ML-driven decisions into conversion funnels.
• Design experiments for decisioning models, defining success metrics and guardrails.
• Monitor model safety and performance in production, tracking latency and data quality.

Skills

Machine learning concepts relevant to personalization

Regression, classification, clustering

A/B testing and controlled experiments

Collaboration with engineers

Structured communication skills

Job description

Work with HelloFresh in Warsaw and its HelloTech organisation, HelloFresh’s global technology backbone with more than 1000 people, building the digital products that power our end-to-end food experience. From meal kits and ready‑to‑eat meals to specialty offerings like pet food and premium meat & seafood, HelloTech creates the platforms that bring tailored food solutions to millions of customers every month.

Our subscription‑based, direct‑to‑consumer model relies on technology at every step, from customer‑facing apps and personalization logic to pricing, forecasting, supply chain optimization, and initiatives that help reduce food waste. While our brands operate independently to serve distinct customer needs, they are united by shared platforms, data, and operational excellence built by HelloTech.

HelloTech works in autonomous, cross‑functional alliances, each owning a specific product or domain end to end. By working with our Warsaw office, you will help shape scalable, data‑driven products used across our markets, working with a modern tech stack and international teams to continuously improve how people discover, order, and enjoy HelloFresh’s products, today and in the future.

The Conversions Tech area enables meal brands to achieve ambitious growth targets through a seamless and high‑performing conversion funnel. As a component of the Growth Alliance, this project drives growth for the HelloFresh group by powering marketing with advanced MarTech capabilities and product innovation. The focus is directed toward (re)acquisition, conversion optimization, and data‑driven growth strategies.

The role

In the capacity of a Senior Data Scientist within Conversions, the service provider contributes to shaping the intelligence that drives customized user journeys across conversion funnels. This involves executing complex feature engineering and optimization efforts, contributing to the data foundations and analytical approaches that power the decisioning platform for personalized experiences.

The provided services enable an automated engine that determines the optimal journey for a specific user at the appropriate time, based on intent, channel, and campaign context. This involves operating in a highly cross‑functional environment, coordinating closely with Product, Engineering, and Marketing to design, evaluate, and scale personalization across various workstreams. This project carries direct responsibility for advancing the data strategy and improving the user experience for the HelloFresh group across global markets.

What You'll Do

• Build and iterate on machine learning models powering personalization that run in production behind high‑traffic, performance‑critical conversion pages.
• Execute decisioning models that determine the best next step in the conversion funnel for each user.
• Contribute to system design by coordinating with Engineering to ensure data science solutions integrate cleanly into the overall funnel architecture.
• Coordinate directly with Product and Engineering to shape how ML‑driven decisions are embedded into the conversion funnels, including where models decide and how failures are handled.
• Direct experimentation design for decisioning models, defining success metrics, guardrails, and how results are interpreted in high‑noise, high‑traffic environments.
• Maintain model safety and effectiveness in production by monitoring performance, input data reliability, and latency, and iterating when issues are detected.

What You'll Bring

• 5+ years of professional experience in data science or a related quantitative field.
• Strong foundation in machine learning concepts relevant to personalization and marketing communications.
• Hands‑on experience with techniques such as regression, classification, clustering, recommendation systems, and experimentation.
• Practical experience designing and analyzing A/B tests and controlled experiments.
• Experience working with customer behavior data and segmentation.
• Extensive experience with operating in production environments and collaborating closely with engineers.
• Clear, structured communication skills and a collaborative mindset.

Above all, we are looking for individuals who will make HelloFresh better. We believe there are many different ways of developing skills and we love diverse experiences! So even if you don’t “tick all the boxes” but think you’d thrive in this role, we would really like to learn more about you.

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.
• Access to workspace at Warsaw Centre Point. The hub offers modern facilities including showers, breakout zones, outdoor space, cycle parking, and refreshments (coffee, soft drinks, and fruit).

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.

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