Senior Data Scientist / Machine Learning Engineer — AdTech & Recommendation Systems

Role overview

We are hiring for a senior-level data science and machine learning role supporting a major mobile advertising platform that operates at very large scale, serving hundreds of millions of users. The position can be aligned to different teams depending on your experience, including real-time bidding optimisation, behavioural prediction at scale, ad ranking, and conversion modelling.

What the role involves

• Design and improve deep learning models for recommendation, ranking, bidding, and behaviour-based prediction, depending on the team you join.
• Create machine learning solutions that are built to handle production-scale workloads using current deep learning methods.
• Work with very large production datasets to lift model quality and support better business outcomes.
• Take models from initial research and experimentation all the way through deployment and A/B testing.
• Partner with engineering and product stakeholders to turn ML work into measurable value for the business.

What this opportunity offers

• Competitive compensation, aligned to experience and seniority.
• A hybrid working setup based in Hamburg, Germany, with relocation and visa assistance available.
• An international workplace where English is the main language.
• Real technical ownership across large-scale deep learning and recommendation systems.
• Strong room for career progression within a fast-moving data science organisation.

Candidate profile

• At least 4 years of experience in Data Science, Machine Learning, or Applied Science.
• Practical experience with deep learning frameworks such as PyTorch and/or TensorFlow.
• Background working on recommendation systems, ranking, or personalisation models at scale.
• Strong Python and SQL skills, plus experience putting models into production pipelines.
• Experience in AdTech, mobile gaming, e-commerce, or another large consumer platform is expected.
• Exposure to real-time bidding or programmatic advertising is a strong advantage for some openings, but it is not mandatory for every role.

Additional notes

This role is for a full-time onsite position in Hamburg, Germany. The role is described as senior and focused on high-impact machine learning work in a fast-paced environment. Applicants interested in confidential discussions are encouraged to express interest.