Senior ML Research Scientist – AI & Generative Recommendation (m/f/d)

2 requirements, read out of the advert rather than guessed from the job title:

• Python
• PyTorch

Also mentioned, not required: Ray, Hugging Face, Trino, Athena, English. Worth having, but their absence is not what gets a CV filtered out.

See how often each of these is required across open data roles in Europe.

adjoe builds the technologies behind mobile app growth and monetization, challenging the status quo of adtech by redefining how apps acquire users and generate revenue. Our two products, Playtime Arcade and adjoe Ads , sit at opposite ends of the mobile advertising spectrum: rewarded engagement and programmatic in-app advertising. Together they run on 13% of the world's smartphones, connecting advertisers, publishers, and hundreds of millions of users, with one goal: making mobile advertising work better for everyone in the ecosystem.

Next-Gen Machine Intelligence for Scalable Discovery & Engagement

The Data Science Research team builds foundational ML representations and advanced AI capabilities that enhance both Playtime and adjoe Ads . Operating as a horizontal deep-tech layer, the team leverages advanced AI and deep learning approaches—specifically generative approaches —to deliver critical systems such as high-dimensional user embeddings , general content understanding and sequential recommendation . These frameworks scale adjoe's products beyond standard industry limitations, utilizing behavioral and transactional data from over 770 million users.

The team operates at the intersection of bleeding-edge R&D and high-scale production engineering, acting as the company’s internal science bar raiser and primary consulting layer for complex ML bottlenecks. The stack is optimized for deep learning and heavy data throughput: PyTorch and [Ray/Hugging Face] for training and fine-tuning foundation models, Trino and Athena for querying massive user-behavior data lakes, and dedicated GPU infrastructure for heavy workloads. The full lifecycle of these AI capabilities is owned by the team—from academic paper translation and offline prototyping to deploying core algorithmic frameworks built to sustain high-throughput, realtime production environments.

Your Mission & Who We Are Looking For:

PhD or equivalent research depth, with a production track record. You have a PhD in CS, Statistics, Math, or Physics, or an MSc with extensive industry research, and publications in top-tier venues like SIGIR, KDD, NeurIPS, or ICLR. You've spent 4+ years building large-scale recommender systems in high-throughput environments: AdTech, e-commerce, or social.