Ml Engineer

PureHealth - CPC; Barcelona; Hybrid; EUR 70,000 - 100,000; Full time

Job summary

Aristocrat is seeking an ML Engineer to join its MLOps team, crafting end-to-end models for games and user experiences. You will design, train, evaluate, and retrain models with a focus on recommender systems, while defining monitoring and governance practices to keep models reliable in production.

You will build robust pipelines, experiment tracking, and model interfaces, collaborating across product and engineering teams.

Qualifications

• 4+ years of experience applying machine learning to real-world problems.
• Proven experience with recommender systems applied to real products.
• Strong Python skills and ML libraries (scikit-learn, PyTorch, TensorFlow, XGBoost).
• SQL expertise and experience with large data warehouses.
• Hands-on experience with experiment tracking and model registry tools (MLflow, W&B, etc.).
• Experience designing model monitoring in production.
• Cloud platforms (GCP, AWS, Azure), Docker, and Airflow.
• Quantitative background in math/CS/engineering.
• Nice to have Snowflake or similar.
• Experience with Generative AI (LLMs) and API integrations.
• Interest in RAG and LangChain frameworks.
• Ability to build simple UIs (Streamlit).

Responsibilities

• Design, train, evaluate and retrain ML models end-to-end.
• Define and monitor model performance, drift, and data quality.
• Establish experimentation and versioning culture for models.
• Create templates and tooling to standardise DS workflows.
• Build robust data pipelines and production-ready code (Python/SQL).
• Explore LLM/RAG projects and expose ML capabilities via simple interfaces.
• Collaborate with product, data and engineering teams and communicate results.

Skills

Python

SQL

ML/DL

Recommender systems

Experiment tracking

Cloud platforms

Docker

Airflow

LLMs

LangChain

Streamlit

Model governance

Tools

MLflow

Weights & Biases

Snowflake

Git

Job description

This job is with Aristocrat, an inclusive employer and a member of myGwork – the largest global platform for the LGBTQ+ business community. Please do not contact the recruiter directly. At Aristocrat, we are advancing gaming technology with modern, powerful solutions. Our mission is to bring happiness to life through play. We value collaboration, creativity, and a strong passion for excellence. These roles primarily support the Machine Learning area of our Product Madness business line — a tech company specialised in social casino mobile games. We are looking for an ML Engineer to join our MLOps team and strengthen its modeling core. You will own machine learning models end to end, from data and experimentation to production, and help us build the monitoring and experimentation culture that keeps them reliable and aligned with the business over time. You will make a real difference in our products and players' experiences.

What You'll Do

Design, train, evaluate and retrain machine learning models with emphasis on recommender systems — that support game features, player experience, and operational efficiency. Own the design of our model performance monitoring: define what to track (drift, data quality, degradation), thresholds, and what "the model is still healthy" means in business terms. Help establish a solid experimentation culture: model versioning and experiment tracking with tools such as MLflow or Weights & Biases, so experiments are reproducible and model versions are easy to compare and promote. Help establish a model governance culture: define how models are promoted to production and lay the foundations of the communication contract between the MLOps team and Data Science. Create templates and cookiecutter scaffolding to standardise how Data Science structures, hands off, and communicates its models and experiments. Build robust training and feature‑engineering pipelines, and write clean, production‑ready Python and SQL. Explore and contribute to early‑stage projects involving LLMs, RAG and agentic AI where they bring value — as a complement to the role, not its core. Develop simple interfaces (e.G., Streamlit) to expose ML capabilities to non‑technical users when useful. Collaborate with teams across product, data, and engineering, and communicate results, limitations, and recommendations clearly across technical and business audiences.

What We're Looking For

• 4+ years of experience applying machine learning to real‑world problems, from data to deployment.
• Proven experience with recommender systems (collaborative filtering, ranking, or similar) applied to real products.
• Strong Python skills and hands‑on experience with ML libraries (scikit‑learn, PyTorch/TensorFlow, XGBoost or similar).
• Solid SQL expertise and experience working with large data warehouses.
• Hands‑on experience with experiment tracking and/or model registry tools (MLflow, Weights & Biases, or equivalent).
• Experience designing or contributing to model monitoring / performance tracking in production.
• Comfort working with cloud platforms (e.G., GCP, AWS, Azure), Docker, and Airflow.
• A strong analytical foundation, with a background in a quantitative field (mathematics, physics, computer science, engineering) or equivalent experience.
• Nice to Have experience with Snowflake or similar cloud data warehouses.
• Hands‑on experience building applications with Generative AI (LLMs), including API integration.
• Interest or early experience in RAG systems — whether through prototypes, side projects, or professional work.
• Interest or familiarity with agentic AI concepts or frameworks (e.G., LangChain agents, CrewAI).
• Ability to build simple user interfaces (e.G., Streamlit) to expose ML models to wider teams.

Why Aristocrat?

Aristocrat is a world leader in gaming content and technology, and a top‑tier publisher of free‑to‑play mobile games. Aristocrat has three operating business units, spanning regulated land‑based gaming (Aristocrat Gaming), social casino (Product Madness), and regulated online real‑money gaming (Aristocrat Interactive). Our team of over 7,300 employees worldwide is united by our company's mission to bring joy to life through the power of play. We deliver great performance for our B2B customers and bring joy to the lives of the millions of people who love to play our casino and mobile games. And while we focus on fun, we never forget our responsibilities. We strive to lead the way in responsible gameplay, and to lift the bar in company governance, employee wellbeing and sustainability. We're a diverse business united by shared values and an inspiring mission to brighten life through the joy found in play.

Travel Expectations

Minimal travel required (up to 5%).

Hybrid role

Hybrid role with 3 days at the office weekly.

Additional Information

Depending on the nature of your role, you may be required to register with the Nevada Gaming Control Board (NGCB) and/or other gaming jurisdictions in which we operate.

Compensation Philosophy

We offer a comprehensive pay and benefits package designed to stay competitive in the market, support your wellbeing, and recognise your contribution to our success. Our approach is underpinned by a pay-for-performance belief in rewarding individual impact. Your specific compensation package will be determined by factors such as your skills, experience, qualifications, and location. Depending on your role and location, you may be eligible for annual bonuses and incentives, health and wellbeing benefits, paid time off, retirement plans, insurance coverage, and other local or statutory benefits. Specific details about compensation and benefits for this position will be discussed during the recruitment process.

This job description may have been reviewed and enhanced using AI-assisted tools to improve clarity, consistency, and inclusivity. All final content, role requirements and hiring decisions remain subject to human review and approval by Aristocrat.