Senior AI/ML Research Scientist (German speaking) (m/w/d) – Deep learning Recommender Systems

adjoe, part of AppLike Group, is seeking a Senior AI/ML Research Scientist to develop and deploy deep learning models for a user base exceeding 500 million. This role involves end-to-end model development, applied research to transfer cutting-edge findings into production, and big data engineering with petabyte-scale datasets. The scientist will validate models through A/B tests, optimize for inference latency, and collaborate with a large international engineering team, transitioning scientific insights into business-driven products.

Must Have

• Conceive, train, and deploy ML models (Transformers, Neural Networks, LLMs).
• Transfer current research findings into productive applications.
• Utilize and shape performant pipelines for petabyte-scale datasets (SQL, S3, PyTorch, TensorFlow).
• Validate models on Business KPIs through daily A/B tests.
• Optimize for inference latency and resource efficiency.
• PhD or Master with excellent grades in Computer Science, Mathematics, Physics, or similar.
• Successful publications at Top-Tier AI/ML Conferences or relevant journals.
• Deep mathematical understanding of modern Deep Learning algorithms.
• Profound programming skills in Python (PyTorch/TensorFlow, ONNX, JAX).
• Negotiation-level German (C2) and fluent English.

Good to Have

• Practical experience with Distributed Computing and Cloud-Infrastructures (AWS, GPU-Cluster H100/A100, Kubernetes, Airflow).
• Programming skills in Scala/Kotlin/Java.

As a global mobile platform, adjoe manages over 500 million users and petabytes of data daily, directly challenging US big tech companies. This German "hidden champion" consistently focuses on technological depth: over 50% of the workforce has an engineering background, ensuring all innovations are developed in-house. With offices on all continents, adjoe, as part of the AppLike Group (Bertelsmann), operates worldwide at the forefront of the AdTech industry. Become part of a fast-growing, international, and motivated team!

Your Mission & Tasks

• End-to-End Model Development: Conception, training, and deployment of your own ML models (focus: Transformers, Neural Networks, LLMs, and others) for a user base of >500 million and 15 billion inferences per day.
• Applied Research: Transferring current research results (papers) into productive applications and developing new architectures beyond standard APIs, and possibly publishing research.
• Big Data Engineering: Use and co-design of high-performance pipelines for processing petabyte-scale datasets using SQL, S3, PyTorch, TensorFlow.
• Production & Testing: Validation of models on business KPIs through daily A/B tests in the live environment and optimization for inference latency and resource efficiency.
• Collaboration: Close cooperation at the interface between your own Research Unit (~15 Data Scientists) and the international Software Engineering Team (~100 experts).
• Science meets Economy: Successful transition from a purely scientific career (focus on details, analysis, and basic research) to business-driven research, where scientific findings serve as enablers to quickly develop and easily validate market-ready products.

Your Profile & Technology Experience

• Academic Excellence: Doctorate (PhD) or Master with outstanding grades in Computer Science, Mathematics, Physics, or comparable quantitative fields.
• Publication: Successful publications at top-tier AI/ML conferences (e.g., NeurIPS, ICML, ICLR, AAAI, CVPR, EMNLP, ACL) or in relevant journals that have undergone a peer-review process.
• Algorithmic Depth: Deep mathematical understanding of how modern Deep Learning algorithms work (optimization, backpropagation, attention mechanisms). High motivation to independently familiarize yourself with new complex issues.
• Coding Expertise: Profound programming skills in Python (PyTorch/TensorFlow, ONNX, JAX) or Scala/Kotlin/Java (nice to have) for integration into Big Data ecosystems.
• Infrastructure Experience: Benefit: Practical experience with Distributed Computing and Cloud Infrastructures (AWS, GPU clusters H100/A100, Kubernetes, Airflow).
• Language: Business fluent German (C2) and fluent English.

We may use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses. These tools assist our recruitment team but do not replace human judgment. Final hiring decisions are ultimately made by humans. If you would like more information about how your data is processed, please contact us.