Data Scientist (Medior)

Data Scientist (Medior)

About Refinery89

Refinery89 is a leading AdTech company helping digital publishers maximize the value of their advertising inventory through advanced programmatic monetization technology. Headquartered in Madrid with a diverse international team we combine data automation and innovation to make digital advertising more transparent efficient and impactful.

We are looking for an experienced and highly analytical Data Scientist (Medior) to join our growing AI and Data team. If youre passionate about building intelligent systems that drive real business impact thrive on solving complex problems and want to shape the future of AdTech innovation wed love to meet you.

What Youll Do

1. Lead the development of advanced statistical and machine learning models to optimize key performance parameters across our platforms (timeouts refresh rates ad placement logic etc.).
2. Design and execute A/B/n experiments to test multiple parameter configurations simultaneously driving measurable improvements in system efficiency and revenue outcomes.
3. Translate data and experimentation results into scalable production-ready solutions that integrate seamlessly with our Product and Engineering teams.
4. Collaborate with cross-functional stakeholdersfrom Product to Commercialto identify high-impact use cases and align technical outcomes with strategic goals.
5. Own the end-to-end lifecycle of models: from ideation data wrangling development and deployment through to performance monitoring and optimization.
6. Present complex findings in a clear and actionable way to both technical and non-technical audiences.
7. Contribute to the continuous improvement of our data science practices tooling and experimentation frameworks.

Who Were Looking For

Experienced Problem Solver

• 2 years of experience in Data Science Machine Learning or related analytical roles ideally in fast-paced digital or AdTech environments.
• Strong analytical mindset with the ability to turn business challenges into data-driven solutions.

Advanced Technical Proficiency

• Strong Python and SQL skills.
• Proven experience with statistical modeling experimentation and machine learning frameworks such as scikit-learn TensorFlow or PyTorch.
• Solid understanding of data manipulation feature engineering and model evaluation techniques.

Cloud Native

• Familiarity with cloud environments such as AWS or Azure.
• Experience deploying and maintaining models within cloud infrastructure.

Experimentation Expert

• Hands-on experience designing running and analyzing A/B and multivariate tests with strong statistical rigor.
• Understanding of experimental design hypothesis testing and causal reasoning.

Communicator & Collaborator

• Able to communicate complex technical concepts clearly to both technical and non-technical stakeholders.
• Comfortable working across multiple teams and functions.

Business-Oriented Thinker

• Understands that the success of an algorithm is measured not only by accuracy but also by its impact on product performance and business outcomes.

Nice-to-Haves

• Background in AdTech programmatic advertising or digital publishing.
• Experience with LLMs causal inference or real-time prediction models.
• Exposure to tools such as Airflow Docker or Spark in production environments.

What You Can Expect from Us

• A fully remote working environment.
• A collaborative international team with a strong knowledge-sharing culture.
• A flat and fast-moving organization inspired by our Dutch roots.
• Opportunities to work on high-impact projects at the intersection of AI data and programmatic advertising.
• Regular team gatherings knowledge-sharing sessions and company events.
• The opportunity to help shape the future of advertising technology through data-driven innovation.

Employment Details

• Permanent contract
• Full-time
• Remote (100%)

Ready to bring science to strategy and shape the future of advertising

Apply today and help us shape the future of programmatic advertising.