Senior Machine Learning Engineer

For this position, you will be required to work several days a week at our office in Hamburg, Sofia, Bucharest or Zagreb.

We are looking for a Senior Machine Learning Engineer to join our central AI/ML Hub and collaborate closely with game studios and other central hubs (Data, Marketing, Ads) to build solutions that drive player experience, operational efficiency, and long-term business impact.

We are at a pivotal stage in scaling AI and ML across the Stillfront Group, with a clear ambition to accelerate and consolidate our efforts in order to make AI and ML a fundamental part of our DNA. This role will be a key enabler in that effort.

This position sits at the intersection of applied machine learning, software engineering, and business problem-solving, helping studios go from experimentation to reliable, scalable ML in production.

As our Senior Machine Learning Engineer, you will be responsible for delivering end-to-end ML solutions, establishing shared tools and workflows, and supporting teams across the organization in adopting ML best practices. You will play a critical role in shaping how ML is built, deployed, and operated across the Stillfront portfolio.

YOUR MISSION

• Lead the design, development, and deployment of production-grade ML models, primarily for personalisation and LiveOps management.

• Own ML systems end-to-end, including data preparation, training pipelines, inference services, monitoring, and iteration.

• Support the development of a central ML platform to enable scalability through reusability and standardization of development workflows.

• Translate product and business problems into scalable ML solutions, balancing model quality, performance, and cost.

• Help define and implement best practices for model lifecycle management, versioning, evaluation, and retraining.

• Collaborate with data engineers and backend engineers to integrate ML systems into live products.

• Mentor and support other ML engineers, helping raise the overall ML maturity of the organization.

• Be our main ML advocate and promote internal knowledge sharing that helps build our AI/ML community.

• Stay up to date with applied ML and MLOps practices and assess their relevance for Stillfront’s needs.

YOUR PROFILE

• 6+ years of experience as a Machine Learning Engineer or similar role, with a proven track record of shipping ML models to production.

• Degree in Computer Science, Data Science, Mathematics or related quantitative disciplines.

• Hands-on experience throughout the full ML lifecycle: from data exploration and feature engineering to deployment and monitoring.

• Strong grounding in machine learning fundamentals and algorithms, with demonstrated ability to select, tune, and evaluate models for real-world problems.

• Solid programming skills, especially in Python, SQL and large-scale data processing languages, as Spark. And experience with common ML frameworks and libraries (e.g. scikit-learn, PyTorch, pyspark, TensorFlow).

• Experience integrating ML models into production systems via APIs, batch jobs, or streaming pipelines.

• Experience contributing to collaborative codebases using Git and familiar with best practices.

• Familiarity with cloud-based environments and production infrastructure, preferably GCP.

• Pragmatic and impact-driven, with the ability to operate in ambiguous environments and turn loosely defined problems into shipped solutions.

Nice-to-have experiences

• Experience contributing to internal ML platforms or shared ML infrastructure.

• Familiarity with MLOps practices such as experiment tracking, CI/CD for ML, and model registries.

• Prior experience in gaming, consumer products, or large-scale data environments.

• Experience mentoring or guiding other engineers in ML-related work.

WHY JOIN US

• Autonomy to explore and implement new technologies, tools, and processes.

• Competitive salary and comprehensive benefits package.

• Work in a dynamic environment with high exposure to a wide variety of genres, tools, and diversified products.

• Flexible working hours and a supportive, collaborative work environment.

• Opportunity to work with a talented team of professionals and make a significant impact on a globally recognized product.

Stillfront Group is a global games company founded in 2010. We develop digital games for a diverse gaming audience and our broad games portfolio is enjoyed by almost 50 million people every month. Stillfront is focused on realizing synergies by connecting and empowering game teams globally through our Stillops platform. We are a fast-growing company and an active global strategic acquirer. Our 1,300+ professionals thrive in an organization that embodies the spirit of entrepreneurship and autonomy.