ML Engineer

Product Madness, Inc.; Barcelona; Hybrid; EUR 60,000 - 90,000; Full time

Job summary

Aristocrat is hiring an ML Engineer to design and deploy ML and AI solutions that personalize player experiences and drive business results. You will work at the intersection of machine learning, software engineering, and AI application development to build scalable models and AI-powered workflows.

You will collaborate with Data Scientists, engineers, and product teams, advancing ML capabilities, experimentation, and production readiness in a hybrid Barcelona setting.

Qualifications

• 2+ years of professional experience in software engineering, ML engineering, or AI development.
• Strong Python programming and software development practices.
• Experience with ML frameworks: scikit-learn, PyTorch, TensorFlow.
• Experience building LLM-based applications, including RAG and tool calling.
• SQL and data retrieval from analytical databases and APIs.
• Experience with cloud platforms, deployment, and CI/CD pipelines.

Responsibilities

• Develop ML solutions: build, train, evaluate, and improve models for prediction, recommendation, and personalization.
• Build AI applications: develop LLM-powered workflows, including input engineering and retrieval-augmented generation.
• Create ML/AI components: produce services and APIs that add ML/AI capabilities to apps.
• Evaluate ML/AI systems: analyze model performance and validate outputs.
• Support production deployment: collaborate with MLOps to deploy and monitor solutions.
• Write clean Python code, tests, and documentation; participate in code reviews.

Skills

Python

ML engineering

LLMs

SQL

Cloud platforms

CI/CD

MLOps

APIs

Education

Education in CS/ML/AI/Math

Tools

Scikit-learn

PyTorch

TensorFlow

GCP

AWS

Azure

Job description

Join Aristocrat, a leading force in the mobile gaming industry, where innovation meets passion! We are dedicated to crafting outstanding gaming experiences and using data to drive strategic business decisions. By joining our collaborative and innovative team, you will have the opportunity to build the future of mobile gaming with your expertise in machine learning and AI.

As an ML Engineer at Aristocrat, you will be key in creating and applying machine learning and AI solutions that boost personalized player experiences and business results. This role provides an outstanding chance to work where machine learning, software engineering, and AI application development meet.

What You'll Do

• Develop ML solutions: Build, train, evaluate, and improve machine learning models for prediction, recommendation, personalization, and decision support.
• Build AI applications: Develop LLM-powered applications and workflows, including on-demand input engineering, retrieval-augmented generation (RAG), and tool integration.
• Construct ML/AI components: Produce software parts, services, and APIs that add machine learning and AI functionality to existing applications.
• Evaluate ML and AI systems: Analyze model performance, verify AI outputs, detect failure modes, and assist in evaluation and testing frameworks.
• Support production deployment: Work alongside MLOps Engineers to deploy, monitor, and maintain ML/AI solutions in production environments.
• Apply engineering guidelines: Write clean, maintainable Python code, implement automated tests, participate in code reviews, and maintain technical documentation.
• Work with complex data: Retrieve, integrate, validate, and prepare datasets from multiple sources for model training, inference, and evaluation.
• Refine existing solutions: Examine technical problems, improve model performance, and support advancements in reliability and efficiency.
• Collaborate across teams: Work with Data Scientists, engineers, and product collaborators to understand requirements and deliver practical ML/AI solutions.
• Develop technical expertise: Continuously acquire new ML/AI technologies, share knowledge, and contribute to engineering discussions and team practices.

What We're Looking For

• Education: BSc, MSc, or PhD in Computer Science, Machine Learning, Artificial Intelligence, Mathematics, or a related technical field, or equivalent experience in practice.
• Experience: 2+ years of professional experience in software engineering, machine learning engineering, or AI development, with practical experience developing ML models or AI-powered applications.
• Software engineering: Strong Python programming skills, including software build, testing, debugging, version control, and collaborative development practices.
• Machine learning: Hands-on experience developing, training, and evaluating supervised learning models using frameworks such as scikit-learn, PyTorch, TensorFlow, or similar.
• Generative AI: Experience building applications using LLMs, including timely query formulation, structured outputs, RAG, and tool calling.
• ML/AI evaluation: Understanding of model evaluation methodologies, performance metrics, and approaches to validating AI outputs.
• ML specialization: Practical experience in at least one area such as recommender systems, time-series modeling, unsupervised learning, or reinforcement learning.
• Data processing: Strong SQL skills and experience retrieving, transforming, and validating data from analytical databases and APIs.
• Production ML: Familiarity with model deployment, inference services, monitoring, and ML lifecycle management.
• Cloud & infrastructure: Working knowledge of cloud platforms (e.g., GCP, AWS, Azure), containers, CI/CD pipelines, and ML development environments.

Nice to have

• Experience in mobile gaming, digital entertainment, or large-scale consumer applications.
• Experience developing recommendation or personalization systems.
• Familiarity with agentic workflows, AI agents, or advanced LLM applications.
• Experience with model serving, distributed computing, or performance optimization.
• Experience working with managed ML platforms such as Vertex AI.
• Familiarity with Bayesian modeling, causal inference, or simulation techniques.

Important Information for Applicants

• CV Language: Please submit your CV in English.
• Hybrid Working Policy: This role follows a hybrid working model, requiring attendance at our Barcelona office 3 days per week.

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.

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.