Founding Data Scientist

This isn't just another data science role. This is an opportunity to build the science function at an AI-native startup helping ecommerce retailers make smarter, more profitable advertising decisions.

Expanly is built for the AI era. We use agents across the company, and we expect everyone — from engineering to the product team — to use modern AI-assisted workflows as a normal part of how we think, build, analyze, and ship.

At Expanly, we're solving a major problem: advertising platforms optimize toward incomplete signals, while retailers care about the business fundamentals that actually matter — margin, inventory, commercial priorities, and long-term profitability. We're building the control center that connects those fundamentals to day-to-day marketing decisions.

Fresh off a funding round and already trusted by leading Nordic retailers, we're looking for a Founding Data Scientist to help us prove and improve the impact of our product. If you're excited about causal inference, predictive modeling, and shipping rigorous methods into real product experiences, we want to talk to you.

The Role

As our Founding Data Scientist, you'll build the first real data science function at Expanly. Your job is not to sit off to the side producing dashboards or notebook experiments that never leave analysis mode. Your job is to help us answer two hard questions at scale: are we truly driving better business outcomes for our customers, and how can we use data to make Expanly itself smarter?

Your first mission is to build scalable ways to measure and validate Expanly's real business impact. That means designing practical approaches for messy real-world conditions where clean experiments are not always available. You'll think deeply about incrementality, causal inference, observational analysis, validation design, and how to turn those methods into capabilities that customers and internal teams can trust.

Your second mission is to improve the product through predictive and optimization methods. That could mean smarter segmentation, better recommendations, prioritization logic, forecasting, anomaly detection, or other model-assisted decision support that helps retailers make better commercial decisions.

Over time, you'll also help us explore how Expanly can responsibly learn across customers and datasets to become more intelligent as our product and data advantage grows. But this is not a speculative research role. We want someone who enjoys turning rigorous thinking into a shipped product.

This is a hands-on role based in Helsinki. You'll work closely with our CTO and our data engineer, and we expect you to move comfortably between scientific reasoning, Python and SQL implementation, and production reality. In a team our size, the work only matters if it ships.

What We're Looking For

We value scientific rigor, product instinct, and the ability to turn hard problems into real systems that customers use.

Applied Science and Product Judgment

• Strong foundation in causal inference, experimentation, observational analysis, applied statistics, or other rigorous methods for understanding real-world business impact
• Experience building predictive models, optimization logic, or decision-support systems that influence product or commercial outcomes
• Ability to choose methods pragmatically and explain trade-offs clearly, especially when the data is noisy or the perfect experiment is not available
• Strong intuition for which problems should be solved with a simple, robust method and which truly justify more sophistication

Engineering and Execution

• Strong Python and SQL skills
• Comfortable working in production codebases, not just notebooks
• Able to collaborate through Git, pull requests, tests, and code review
• Comfortable working with messy, high-volume data from multiple sources and turning it into robust, explainable outputs
• Excited about shipping alongside engineers in a small, high-ownership team

How You Work

• Clear written and spoken communication
• Comfortable using modern AI-assisted tools to accelerate analysis, coding, experimentation, and iteration, while maintaining high standards for rigor and correctness
• High ownership and a bias toward making progress
• Enjoy working closely with teammates in person and contributing to a strong office culture in Helsinki

We expect this role to land at the senior level, but we'd also be excited to talk to exceptional mid-level candidates who have unusually strong builder instincts and applied-science maturity.

We welcome candidates with or without a PhD. Advanced academic training is great, but what matters most is whether you've used rigorous methods to solve real-world problems and turn them into shipped outcomes.

Nice to Have

• Experience in ecommerce, adtech, retail media, growth, experimentation, pricing, marketplaces, or another data-rich commercial domain
• Experience in an early-stage startup where you had to move between strategy, analysis, and hands-on implementation
• Experience productizing models or decision-support systems rather than stopping at prototypes
• Familiarity with marketing measurement, incrementality, attribution, or commercial optimization problems

Domain experience is a strong plus, but not a hard requirement if you've solved similarly messy commercial or product problems in another domain.

What We Offer

Compelling compensation package with life-changing equity:

• Competitive Base Salary: €60,000 – €78,000 per year, based on your experience and impact. Your specific salary within this range will be determined by your level of experience and alignment with our internal compensation framework, ensuring fairness across the team.
• Foundational Team Equity: As a core member of our founding team, you won't just get options; you'll get a meaningful stake in the company. Our goal is to build a company with a valuation exceeding 100M€ in the next four years. For a foundational team member, an equity stake of this size could be worth well over 1,000,000€. This is your opportunity to own a piece of the engine you help build and share directly in our monumental success.

• A front-row seat to the future of ecommerce and advertising technology
• Direct influence on product direction, science direction, and company strategy
• The chance to work on hard, high-leverage problems with immediate customer impact
• A Helsinki-based hybrid setup with at least 3 days per week in the office for the Product and Engineering team
• A culture of ownership, trust, and low bureaucracy
• Modern tools, strong technical teammates, and a real opportunity to define an important function from the ground up

About Expanly

Founded in Helsinki, Finland, Expanly helps ecommerce retailers make better advertising decisions by connecting operational reality to marketing execution. We bring together signals like product data, advertising performance, margin, and inventory so retailers can prioritize what actually drives profitable growth.

We're building a category-defining product for retailers who want more control, better measurement, and smarter decision-making than the major ad platforms can offer on their own. With strong early traction, ambitious customers, and fresh backing for growth, we're at the point where the next few hires can shape the company in a very real way.

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