Machine Learning Engineer

About adjoe

adjoe is a leading mobile ad platform developing cutting-edge advertising and monetization solutions that take its app partners’ business to the next level.

As part of the applike group and backed by Bertelsmann, we combine a powerful tech ecosystem, strong financial support, and a motivated team to compete with industry giants.

Meet Your Team: Programmatic Data Science

Did you know that in-app ads are sold in real-time auctions, within milliseconds, before they appear in thousands of mobile apps? Our in-house ad network competes in this fast-paced ecosystem against Google, Meta, TikTok, and others — to win impressions and serve the best-performing ads.

The Programmatic Data Science team is at the forefront of this competition, designing high-impact algorithms based on real user behavior and business goals. We quickly turn research into scalable production systems — leveraging cutting-edge tech and working cross-functionally with product and business teams.

What You Will Do

• Architect and deploy a high-throughput, low-latency recommendation system for millions of users and billions of daily requests
• Identify key signals from large-scale datasets to enhance model performance
• Develop and refine relevance models and bidding strategies using advanced ML techniques to directly impact company revenue
• Own the end-to-end lifecycle of ML models — from deployment and monitoring to performance analysis and iterative improvement
• Collaborate with backend engineers to deliver robust, production-ready ML solutions and reusable model assets
• Run A/B testing and experimentation to validate hypotheses and measure feature impact on key business metrics

Who You Are

• 2+ years of experience building and deploying production-grade recommendation systems in high-volume environments (e.g. adtech, e-commerce, search)
• Proven expertise in deep learning and recommendation models using TensorFlow, PyTorch, or JAX
• A software engineer at heart, with a strong coding mindset and clean development practices
• Bonus: Familiarity with data engineering principles
• Bonus: Experience with large-scale distributed systems (e.g., Spark, Flink, Kafka) and data storage (e.g., AWS Athena, S3, MySQL)

Fuel for the Journey: Benefits to Support Your Ambitions

• Invest in Your Future: Regular feedback and a structured development program help you grow and reach your career goals
• Easy Relocation: From visa to moving, we support your relocation to Hamburg — including a bonus and German classes
• Hybrid Work Culture: Enjoy 3 core office days, flexible hours, 30 vacation days, and 3 weeks of remote work per year
• Well-being First: Access our in-house gym, attend fitness classes, and get mental health support via our EAP
• Modern Workspace: Work with top-notch equipment and enjoy lake views, open spaces, and a variety of snacks and drinks
• Be Part of the Community: Join hackathons, social gatherings, and team events — we build and celebrate success together