Data Scientist

2 days ago

Belgrade, Central Serbia AdTech Holding Full time €40,000 - €80,000 per year

AdTech Holding is an Innovation hub based in Cyprus, which creates vibrant startup ecosystems and technologies for AdTech & MarTech projects.

Since 2011, AdTech Holding has been a starting point for an array of industry-leading advertising and digital marketing companies (PropellerAds, Zeydoo etc). Holding brings the most daring ideas to the market and creates cutting-edge solutions to deliver technology globally.

We are looking for a Data Scientist to join our Research & Analytics Team.

We have a strong team with a rich culture of ML and AI technologies, developed over more than 10 years

About the Team

The Research & Analytics team at PropellerAds applies Machine Learning to build advertising recommendation algorithms (CTR Prediction, Ranking), optimize bidding in Real-Time Bidding, segment users, and assess traffic quality.

Our solutions handle billions of requests daily and impact the experience of hundreds of millions of users worldwide.

We work with Python, Airflow, Vertica, Amazon Sagemaker, PyTorch, and Docker.

What You'll Do

  • Develop ML models for recommendation systems and auction optimization.
  • Apply modern techniques such as Multi-Armed Bandits, Reinforcement Learning, and Counterfactual Learning.
  • Work across the entire ML pipeline — from data and feature engineering to production inference.
  • Collaborate closely with backend engineers, contribute to infrastructure design, and participate in A/B testing of models.
  • Monitor metrics and model performance after deployment.
  • Communicate with business stakeholders, analyze corner cases, and identify opportunities to improve the system together.

What We Expect

  • 3+ years of experience developing and deploying ML models in production.
  • Strong knowledge of classical Machine Learning algorithms.
  • Excellent skills in Python, pandas, and scikit-learn.
  • Solid understanding of probability theory, statistics, and basic Reinforcement Learning principles.
  • Ability to turn vague business problems into clear, structured tasks and suggest appropriate models or solutions.

Nice to Have

  • Experience in AdTech or Recommender Systems.
  • Experience working with SQL and large-scale data.
  • Knowledge of Airflow and Docker.
  • Familiarity with deep learning frameworks — PyTorch, TensorFlow, or JAX.
  • Ability to design solutions with latency and high-load considerations (highload ML).


We offer freedom of choice: with us, you'd have a cafeteria benefits system where you can choose which benefits would fit your individual needs.
And, of course, a standard pack of benefits as well: health insurance, fully covered 10 working days of sick leave per year, 5 additional day-offs per year, English and other languages compensation, quartile, and annual bonuses, corporate events, gifts, also food (yummy) - you can find snacks in our worldwide working spaces and breakfasts & lunches in the offices

  • Senior Data Scientist

    6 days ago

    Belgrade, Central Serbia SMG Serbia Full time €30,000 - €60,000 per year

    Welcome to SMG Swiss Marketplace Group AGWe are a pioneering network of online marketplaces and a leading European digital company that simplifies people's lives with forward-looking products.A little bit about us to help ignite your imaginationSMG Swiss Marketplace Group AGcame together following the merger of Scout24 Switzerland and TX Markets in 2021. A...

  • Data Engineer

    6 days ago

    Belgrade, Central Serbia Publicis Sapient Full time €60,000 - €80,000 per year

    Job DescriptionTremend is looking for a Data Engineer to join our team of bright thinkers and doers. You'll use your problem-solving creativity to figure out our client's most complex and challenging problems across different industries. We are on a mission to transform the world, and you will be instrumental in shaping how we do it with your ideas,...

  • Senior Data Scientist

    2 days ago

    Belgrade, Central Serbia Telesign Full time €30,000 - €60,000 per year

    Key Responsibilities:Six plus years of relevant experience;DS/ML/AI products design, prototyping, development, deployment, upgrades, maintenance rebuilding/retraining, customizations, etc. for all DS/ML/AI-driven solutions;Data sources and data partners R&D: identification, research, cleansing, evaluation, patterns recognition, feature prototyping and...

  • Senior Data Scientist

    2 days ago

    Belgrade, Central Serbia Telesign Full time €30,000 - €60,000 per year

    Key ResponsibilitiesSix plus years of relevant experience;DS/ML/AI products design, prototyping, development, deployment, upgrades, maintenance rebuilding/retraining, customizations, etc. for all DS/ML/AI-driven solutions;Data sources and data partners R&D: identification, research, cleansing, evaluation, patterns recognition, feature prototyping and...

  • Data Engineer

    4 days ago

    Belgrade, Central Serbia Camlin Group Full time €30,000 - €60,000 per year

    About Camlin Group:Camlin is a global technology leader that operates with the vision of bringing revolutionary products to life for a wide range of industries, including power and rail, and also has interests in a number of R&D projects in a variety of scientific sectors.At Camlin we believe in high quality engineering and design, allowing us to develop...

  • Data Mining Engineer

    7 days ago

    Belgrade, Central Serbia CETIN Serbia Full time €40,000 - €80,000 per year

    About us:As a leading telecommunications infrastructure provider in the region, CETIN drives digital transformation with a strong presence across Bulgaria, Hungary, Serbia, and Slovakia. Through our subsidiaries, we deliver advanced technology solutions that empower connectivity and enable innovation.CETIN owns and operates some of the largest...

  • Data Engineer II

    2 weeks ago

    Belgrade, Central Serbia Rivian Full time 30,000 - 60,000 per year

    About RivianRivian is on a mission to keep the world adventurous forever. This goes for the emissions-free Electric Adventure Vehicles we build, and the curious, courageous souls we seek to attract. As a company, we constantly challenge what's possible, never simply accepting what has always been done. We reframe old problems, seek new solutions and...

  • Data Solutions Architect

    2 weeks ago

    Belgrade, Central Serbia Merkle Full time €30,000 - €60,000 per year

    Job Description:WeDream. WeDo. WeDeliver.About MerkleFor more than 35 yearsMerkle, a dentsu company we have putpeopleat the heart of our approach to digital business transformation. As the only integrated experience consultancy in the world with a heritage in data science and our performance, Merkle delivers holistic experience that promotes growth,...

  • AI/ML DevOps Engineer

    2 weeks ago

    Belgrade, Central Serbia NTT DATA Europe & Latam Full time €45,000 - €90,000 per year

    Who We AreJoin our global Centre of Excellence as a subject matter expert (SME) for Agentic AI Services, collaborating with teams worldwide to drive innovation and excellence. As part of this central function, you will help shape, implement, and scale cutting-edge Agentic AI solutions across the organization and our clientsThe AI/ML DevOps Engineer is a...

  • Applied AI Research Lead

    1 week ago

    Belgrade, Central Serbia Toloka Full time €40,000 - €80,000 per year

    Company IntroAtToloka AIwe create data that powers leading GenAI models and innovations. We work with frontier labs, big tech, renowned AI startups, enterprises and non-profit research organizations worldwide. We use a combination of Experts + Crowd + Tech Platform to teach AI models to reason and evaluate their efficacy and safety. We have experts in more...