Senior Data Scientist (f/m/d)

adjoe is a leading mobile ad platform developing cutting‑edge advertising and monetization solutions that take its app partners’ business to the next level. Part of the applike group ecosystem, adjoe is home to an advanced tech stack, powerful financial backing from Bertelsmann, and a highly motivated workforce to be reckoned with.

Meet Your Team: Programmatic Data Science

Did you know that in‑app ads are sold in a real‑time auction before they get rendered in thousands of mobile apps? Dozens of ad networks compete for every single view, choosing their best ad and deciding what price to bid in just a couple hundred milliseconds. We at adjoe have developed our own ad network that takes part in this competition, going against industry giants to present our own ads.

In the competitive real‑time bidding landscape, the Programmatic Data Science team operates at a rapid pace, developing cutting‑edge algorithms to create systems that outperform industry giants. Our approach is deeply rooted in rigorous research into user behavior, publisher and advertiser objectives, ensuring an optimal user experience. We are a fast‑moving team that rapidly translates theory into impactful solutions, using state‑of‑the‑art technologies and collaborating closely with product and business stakeholders.

What You Will Do

• Architect and Refine Relevance Models: design and implement sophisticated targeting models that understand user preference within the dynamic ad tech ecosystem. Drive significant improvements in ad performance and user engagement through machine learning techniques.
• Explore Policy Optimization Strategies: Develop and optimize bidding policies using Bayesian method, reinforcement learning and other advanced optimization algorithms. Continuously refine these policies to maximize business KPI and adapt to the ever‑changing real‑time bidding landscape.
• Build and Deploy Meta‑Learning Frameworks: Create and implement meta‑models that learn from user interactions, enabling personalized ad experiences.
• Conduct rigorous A/B testing and experimentation: Validate your hypothesis and measure the impact of new features on key business metrics.
• Bridge Ideation and Production: Harden successful experiments into highly scalable solutions. You will take end‑to‑end ownership of your models within our modern ML stack (Python, Kubernetes on AWS, Airflow, MLFlow, Trino), balancing speed‑to‑market with robust engineering principles.
• Act as a Team Multiplier: Proactively share your specialized knowledge and engage in healthy architectural debates. You foster a collaborative environment where direct, constructive feedback pushes the entire team to excel.

Who You Are

• You have 4+ years of professional experience in the Data Science field working in AdTech, mobile gaming, e‑commerce or a similar industry.
• You have a track record of architecting and deploying machine learning solutions, with strong expertise in real‑time large scale recommender systems and neural networks.
• You are completely comfortable navigating a sophisticated, distributed engineering environment that produces massive amounts of data. You write excellent Python and SQL, with hands‑on experience integrating models into automated training and deployment pipelines.
• You possess a strong foundation in mathematical concepts and are skilled at translating complex algorithms into clear, concise explanations for both technical and non‑technical audiences.
• You are highly pragmatic and solutions‑oriented. You know how to balance the pursuit of technical excellence with the need for velocity, recognizing when an 80% solution is exactly what the business needs to make an immediate impact.
• You value clear, direct, and kind communication. You are a strong team player who enjoys helping others and engages in productive technical discussions.

Fuel for the Journey: Benefits to Support Your Ambitions

• Invest in Your Future: Regular feedback and our development program support your growth, helping you expand your skillset and achieve your career goals.
• Easy Arrival to adjoe: From signing to settling in Hamburg, we’ve got you covered. Need a visa? No problem. Ready to build your new life and career at adjoe in Hamburg? We support every ambition—from learning German to a relocation bonus that helps you settle in and make Hamburg feel like home.
• Live Your Best Life, at Work and Beyond: We work in a hybrid setup with 3 core office days, plus flexible working hours. Enjoy 30 vacation days, 3 weeks of remote work per year, and free access to an in‑house gym with lots of different fitness classes and mental health support through our Employee Assistance Program (EAP).
• Thrive Where You Work: Enjoy the Alster lake view from our central office with top‑note equipment, fun open spaces, and a large variety of snacks and drinks.
• Join the Community! Participate in regular team and company events, including hackathons and social gatherings. We work together, and we celebrate together, too.

Our mission is to create an inspiring work environment for amazing people to achieve extraordinary things. Be part of it!

Skip writing cover letters. Tell us about your most passionate personal project, your desired salary, and your earliest possible start date. We are looking forward to your application!

We welcome applications from people who will contribute to the diversity of our company.