Senior Data Scientist (f/m/d)
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:
4+ years in Data Science, ideally in AdTech or a high-volume consumer product. You have a track record of architecting and deploying large-scale recommender systems and neural networks in production. At adjoe Ads, that means owning models that influence 10 billion daily predictions in a real-time bidding environment.
Relevance modeling and policy optimization are your core. You design targeting models that understand user preferences at scale, and develop bidding policies using Bayesian methods, reinforcement learning, and other advanced optimization algorithms, continuously adapting them to the real-time bidding landscape.
End-to-end ownership, not just research. You harden successful experiments into scalable production solutions using Python, Airflow, MLflow, Trino, and Kubernetes on AWS. You balance speed-to-market with engineering rigor, and know when an 80% solution is exactly what the business needs.
Comfortable in a sophisticated distributed environment. You write excellent Python and SQL, have hands-on experience with automated training and deployment pipelines, and can navigate a stack producing massive amounts of data across a several hundred TB of data without losing sight of the business goal.
Strong mathematical foundation, clear communicator. You dive deep into complex algorithms and translate them into clear explanations for both technical and non-technical audiences. You engage in direct, constructive architectural debates and actively raise the technical bar around you.
🌎 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.