Python Machine Learning Engineer (Hybrid - Madrid)

Role description We are still looking for the very Top Talent…and we would be delighted if you were to join our team! More in details, UST is a multinational company based in North America, certified as a Top Employer and Great Place to Work company with over 35.000 employees all over the world and presence in more than 35 countries. We are leaders on digital technology services, and we provide large-scale technologic solutions to big companies. What we look for? A passionate Machine Learning Engineer with experience in Generative AI, Large Language Models (LLMs), AI Agents, and MLOps/DevOps environments, eager to help design, build, and deploy enterprise-grade AI solutions. Required to go to the client's offices in central Madrid 3 days a week. High english level is required. Key Responsibilities: • Develop, deploy, and optimize Machine Learning and AI solutions for complex business challenges. • Design and implement multi-agent systems and enable AI models with function/tool-calling capabilities. • Build and maintain Retrieval-Augmented Generation (RAG) solutions using enterprise data. • Evaluate, integrate, and optimize AI models, including Large Language Models (LLMs). • Design and improve agentic workflows and AI agents for production environments. • Test and optimize prompts and few-shot examples to ensure accurate, consistent, and safe AI outputs. • Evaluate model performance using appropriate metrics, benchmarks, and validation techniques. • Collaborate with Data Scientists, Data Engineers, Platform Teams, and other stakeholders. • Participate in code reviews, testing, debugging, and quality assurance activities. • Contribute to the full AI lifecycle, from design and development to deployment and monitoring. Mandatory requirements: • Bachelor’s or Master’s degree in Computer Science, Data Science, Mathematics, Statistics, or a related field. • Strong programming skills in Python. • Hands-on experience with Machine Learning frameworks such as TensorFlow and/or PyTorch. • Proven experience working with Large Language Models (LLMs). • Solid understanding of AI Agents, agentic workflows, orchestration frameworks, and reasoning patterns. • Experience designing and implementing RAG architectures. • Knowledge of data preprocessing, feature engineering, model selection, and evaluation techniques. • Strong understanding of statistics, probability, linear algebra, and optimization concepts. • Experience applying software engineering best practices, including version control, testing, and documentation. • English C1 Nice to have: • Experience working in cloud environments (Azure, AWS, or GCP). • Knowledge of MLOps and CI/CD practices. • Experience deploying and monitoring AI solutions in production. • Background in financial services, banking, or wealth management. • Familiarity with vector databases and modern GenAI ecosystems. ¿What can we offer? • 23 days of Annual Leave plus the 24th and 31st of December as discretionary days! • Numerous benefits (Heath Care Plan, Internet Connectivity, Life and Accident Insurances). • `Retribución Flexible´ Program: (Meals, Kinder Garden, Transport, online English lessons, Heath Care Plan…) • Free access to several training platforms • Professional stability and career plans • UST also, compensates referrals from which you could benefit when you refer professionals. • The option to pick between 12 or 14 payments along the year. • Real Work Life Balance measures (flexibility, WFH or remote work policy, compacted hours during summertime…) • UST Club Platform discounts and gym Access discounts If you would like to know more, do not hesitate to apply and we’ll get in touch to fill you in details. UST is waiting for you! In UST we are committed to equal opportunities in our selection processes and do not discriminate based on race, gender, disability, age, religion, sexual orientation or nationality. We have a special commitment to Disability & Inclusion, so we are interested in hiring people with disability certificate. #UST Skills Python, TensorFlow, Machine Learning About UST UST is a global digital transformation solutions provider. For more than 20 years, UST has worked side by side with the world’s best companies to make a real impact through transformation. Powered by technology, inspired by people and led by purpose, UST partners with their clients from design to operation. With deep domain expertise and a future-proof philosophy, UST embeds innovation and agility into their clients’ organizations. With over 30,000 employees in 30 countries, UST builds for boundless impact—touching billions of lives in the process.