Senior ML Research Engineer – AI & Generative Recommendation (m/f/d)
- Berlin
- adjoe
- Data Science Research
- Full time
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.
You translate research into production, not just prototypes. You distill SOTA research into robust, production-ready code optimized for sub-millisecond latency. At adjoe, that means architecting multi-stage recommendation pipelines, Generative Retrieval, Deep Ranking, and Re-ranking, serving millions of requests across a stack built on 770 million users’ behavioral data.
Deep expertise in PyTorch and large-scale model optimization. You have hands-on experience with high-concurrency optimization, model quantization, and distillation, the engineering side of getting large generative models to run under extreme production constraints, not just in research environments.
Content understanding and embeddings are core to your work. You research and develop information-rich user and ad embeddings using unsupervised and generative approaches, directly improving the quality of predictions across both Playtime and adjoe Ads.
Raises the technical bar around them. You lead architectural debates, mentor junior scientists, and drive the team’s research direction without needing a roadmap handed to 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.
Tips & Tricks to Nail Your Interviews!
Skip cover letters
Check your equipment
Do some research
Prepare an elevator pitch
Structure your answers
Let your personality shine
Come with your questions
Don’t be afraid of rescheduling
Recruiting FAQs
We aim to make our recruiting process as fast and efficient as possible, but the duration can vary depending on the role you are applying for. Usually we are really fast, though (less than 4 weeks).
Yes, if you see multiple roles open that match your skill set, you can apply for them simultaneously. Our Talent Acquisition team will review your application and contact you about the role that best seems to match your skills.
Yes, if you see multiple roles that match your skill set, you can apply for them simultaneously. Our Talent Acquisition team will review your application and contact you about the role that best matches your skills.
Great! Please allow a few days for our team to review your application. We will contact you with the next steps as soon as possible.
We’ll never ask you for money, fees, or sensitive information (like bank details, tax forms, or credit card numbers) during the hiring process.
If anything feels off, you can always double-check by reaching out to our Talent Acquisition team at ta@applike-group.com.
Once you’ve signed your contract, our HR team may request personal details, but only from our official email: hr@applike-group.com.
No, we do provide full visa and relocation support.
We do! You can find more information about our relocation support and the succesful relocation of our colleagues here on this website.
No problem! Our visa and relocation support does also include your partner or kids. (Please be aware that legal marriage is often times a requirement to obtain a partner-visa).
If you prefer 100% remote companies, applike is not the right place for you because we strongly believe in face-to-face collaboration. However, we did implement a hybrid working model where we are in the office at least three days a week (Monday, Tuesday, and Thursday) and can work remotely the remaining two days. Additionally, you get three whole weeks per year to work fully remotely if you want.
Our hybrid working approach involves being in the office at least three days a week (Monday, Tuesday, and Thursday) and the option to work remotely the remaining two days. Flexible working hours mean that we work Monday-Friday, but do not have fixed working hours. Just make sure to adapt to the rhythm of your team.
The headquarters of the applike group and all its subsidiaries are located in Hamburg, Germany. We do have offices in the US and APAC.
Well next to the fact that you are able to see and collaborate with your colleagues face-to-face, we have a super modern office that leave no wishes open: from Drinks & Snack, areas to work away from your desk to a fully equiped gym.
Yes, you can!
Couldn’t find the perfect job offer?
Nevermind! We are always interested to get in touch with new talents.