Senior Machine Learning Engineer (Product) – Fixed-Term ContractLocation: Madrid or Barcelona (Hybrid)Contract: Fixed-term until June 2026We're looking for a Senior Machine Learning Engineer to join a leading European deep-tech company at the cutting edge of AI innovation. This is a chance to make real impact on next-generation large language model (LLM) solutions that are redefining how AI is built, optimized, and deployed.What You'll Do- Build, optimize, and scale data pipelines for LLM training and fine-tuning.- Develop techniques for data sourcing, cleaning, validation, and enhancement.- Work cross-functionally with ML engineers and researchers to deliver production-ready, high-performance models.- Implement and test advanced compression and optimization methods for AI models.- Stay ahead of trends in LLM architectures, evaluation, and dataset curation.What You'll Bring- Master's or PhD in Computer Science, AI, Data Science, or related field — or equivalent experience.- 4+ years of hands-on experience in ML or NLP (especially with LLMs).- Strong Python skills and familiarity with libraries such as Hugging Face, Pandas, and NumPy.- Experience managing large-scale datasets and distributed computing environments.- Collaborative mindset and solid understanding of modern ML development practices.What's on Offer- Competitive salary (from €60,000 per annum).- Fixed-term contract until June 2026 with signing and completion bonuses.- Hybrid working model – flexible hours with regular on-site collaboration.- Opportunity to work on cutting-edge AI technology within a fast-scaling, international environment.This role offers a unique opportunity to work on impactful AI engineering projects while enjoying flexibility, collaboration, and exposure to world-class research and development.