ML Engineer — Agents & LLMs

About the company: KIEFER is building Greece's integrated AI ecosystem. From renewable energy infrastructure and AI systems to robotics and enterprise applications, we connect the technologies that power Europe's intelligent future. Founded in 2014, KIEFER has delivered 600MW+ of energy projects and is now developing sovereign AI infrastructure, enterprise AI products and physical AI systems for Greece and Southeast Europe. About the role We are looking for an ML Engineer to improve the agent and long-context LLM capabilities behind Kiefer Tech’s AI products. You will work hands-on across post-training, data, evaluation, agent design, and inference, with the goal of making multi-step tasks more reliable in production. What you will do - Run post-training experiments using supervised fine-tuning, preference optimization, reinforcement learning, or other suitable methods. - Improve how agents plan, use tools, manage execution, and recover from errors. - Build benchmarks, verifiers, and diagnostic tools to measure agent performance and identify failures. - Generate and curate training data, including agent trajectories and difficult cases from target workflows. - Evaluate and improve ... Click Apply to read the full job description.