Data Science Director (f/m/d)

Title: Data Science Director (f/m/d) Company: adjoe Location: Hamburg / Hybrid / Remote

adjoe builds the technologies behind mobile apps growth and monetization. adjoe Ads is our programmatic in-app advertising platform that seamlessly connects advertisers and publishers through direct integration of our Android and iOS SDKs. Every ad decision happens in under 200ms across 10 million daily users, powered by real-time bidding algorithms and user quality prediction models that match the right ad to the right user at the right moment.

50 Billion Daily Bid Predictions

The adjoe Ads Data Science team owns the entire bidding algorithm that decides which ad you are most likely to enjoy from start to finish: conversion prediction, user quality estimation, and bid shading. Every bid adjoe placed in an ad auction is the output of ML models making 50 billion predictions daily, trained on data from our mobile SDKs that capture real user behavior at scale.

The team moves fast: new ideas tested offline, A/B tests launched in production within minutes. We rely on industry-proven state of the art technology, adapted to our needs and self-hosted where it matters: PyTorch and TensorFlow for modeling, Trino and Athena for querying a 350TB Iceberg data lake, Airflow and Ray for orchestrating our different training pipelines across multiple GPU clusters. Models are built on 600+ features and trained on 200 million data points, with the full ML lifecycle owned by the team from research and experimentation to deployment and real-time inference at sub-200ms latency.

Your Mission & Who We Are Looking For:

• 5+ years in Data Science, 2+ in leadership. You have a track record of architecting and deploying ML solutions, recommender systems and neural networks specifically, and have led data science teams through hiring, mentoring, regular 1-1s, and career development. At adjoe Ads, you'll be growing and managing the team of Data Scientists, Data & ML Engineers, Data Analysts that owns the entire bidding algorithm.
• At least 50% hands-on. This is not a purely managerial role. You work on data science tasks yourself, own critical procedures like experiments and implementation details, and mentor data scientists in advanced modeling, programming quality, and strategic thinking.
• Fluent in data at scale. You've worked with large, diverse data sources AWS Athena, Kafka, Spark, Flink, S3, MySQL and know how to extract signals from a 350TB data lake. Strong Python required; experience building an MLOps stack with Airflow, Spark, or Flink is a strong plus.
• Bridges math and business. You can dive deep into mathematical foundations and translate complex model behavior into clear decisions for product and business stakeholders. You align with the adjoe Ads product team and Cloud Infrastructure on priorities, tools, and best practices.
• Contributes to the roadmap, not just the backlog. You work on long-term strategy and quarterly OKRs, contributing to adjoe Ads' position as a strong competitor in the programmatic adtech market.

🌎 We welcome applications from talent worldwide and provide relocation support to Hamburg, Germany for those ready to join our team.

What’s in It for You?

At adjoe, you’re not here to just close JIRA tickets, you’re helping build the infrastructure behind one of the most impactful platforms in adtech. The systems you work on will reach hundreds of millions of users and power billions of decisions every day.

• Go Big. Own projects with impact on 770M users and push adtech boundaries.
• Move Fast. Ship solutions multiple times a day, learn from results, and keep momentum.
• Be Direct. Solve problems openly and collaborate across teams.
• Thrive Together. Grow with a diverse, global team of people from over 40 different countries that learn from each other.
• Have Fun. Celebrate wins, enjoy daily victories, and bring your energy.

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