Senior ML Engineer (LLM)

Senior ML Engineer (LLM) @ Kiefer Senior ML Engineer (LLM) Location Athens Employment Type Full time Location Type Hybrid Department Technology Compensation - Annual gross base salary €80K – €160K About the company: Kiefer Tech, the technology arm of Kiefer, leverages over 12 years of engineering heritage from the Green Energy sector to deliver cutting-edge AI, robotics, and enterprise solutions across Greece and the EU. We build sovereign AI infrastructure that keeps data within EU borders, respect privacy, and delivers tangible business impact. Guided by our core values: innovation, quality, and long-term client partnerships, we create enterprise-grade AI infrastructure, the first true Greek Large Language Models, and intelligent automation solutions that empower organizations to thrive. Our strategic collaboration with NVIDIA combines sustainable infrastructure expertise with world-class AI technology, creating an ecosystem that fosters innovation, strengthens Greece’s technological sovereignty, and generates real impact across industries. Join us and help build the AI-powered world of tomorrow. About the role: We are looking for a Senior Machine Learning Engineer to join Kiefer Tech and strengthen our ML Engineering team. In this role, you will work on the development and continuous improvement of Sophea AI, our Greek-focused Large Language Model. You will be deeply involved in LLM pre-training, training from scratch, fine-tuning, model evaluation, inference optimization, and production-grade ML systems. This is a hands-on engineering role for someone who has already worked directly with language models and understands how to improve their quality, performance, and reliability in real production environments. Important: this role requires strong practical experience with LLM development. Classical ML, computer vision, basic RAG, or high-level AI tools alone will not be enough for this position. What you will do: - Work on So