ML Engineer (Recommender Systems)

Location: Barcelona, Spain

Company

hirify.global develops gaming technology and free-to-play mobile games through its Product Madness business line, with a focus on social casino products.

What you will do

• Design, train, evaluate, and retrain machine learning models, especially recommender systems for game features, player experience, and operational efficiency.
• Define model monitoring for drift, data quality, degradation, thresholds, and business-level health criteria.
• Establish experiment tracking, model versioning, and reproducible workflows using tools such as MLflow or Weights & Biases.
• Define model promotion and governance practices between MLOps and Data Science.
• Build standardized templates, training pipelines, feature-engineering pipelines, and production-ready Python and SQL solutions.
• Contribute to LLM, RAG, and agentic AI initiatives and develop simple interfaces such as Streamlit applications when useful.

Requirements

• 4+ years of experience applying machine learning to real-world problems from data preparation through deployment.
• Proven experience with recommender systems, including collaborative filtering, ranking, or similar methods.
• Strong Python skills and experience with scikit-learn, PyTorch, TensorFlow, XGBoost, or comparable ML libraries.
• Solid SQL skills and experience with large data warehouses.
• Experience with experiment tracking, model registries, and production model monitoring.
• Experience with cloud platforms, Docker, Airflow, and quantitative problem-solving.

Nice to have

• Experience with Snowflake or similar cloud data warehouses.
• Experience building Generative AI applications and integrating LLM APIs.
• Interest or experience with RAG systems and agentic AI frameworks such as LangChain agents or CrewAI.
• Ability to build simple Streamlit interfaces for wider teams.

Culture & Benefits

• Collaboration across product, data, and engineering teams.
• Work focused on responsible gameplay, governance, employee wellbeing, and sustainability.
• Annual bonuses and incentives may be available depending on role and location.
• Benefits may include health and wellbeing support, paid time off, retirement plans, insurance, and local statutory benefits.
• Minimal travel required, up to 5%.